• Metamaterials'2020
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28 September 2020 / Start time: 8 h 30 min
08:30 - 09:00 - Opening Ceremony
09:00 - 10:00 - Plenary Session I
09:00 - Plenary Session I

Session chairperson(s): Stefano Maci

09:00 - 10:00 - Metastructures with Four Dimensions and High Degrees of Freedom Plenary [Show abstract]
  • Nader Engheta, University of Pennsylvania, USA
<p> We discuss how selective spatiotemporal variation of different material parameters can provide us with higher degrees of freedom and richer functionality and dimensionalities in manipulating wave interaction with such platforms. Several scenarios are presented and potential applications of such metastructures are mentioned.</p>
10:00 - 10:30 - Coffee Break (Monday Morning)
10:30 - 12:30 - Oral Sessions (Monday Morning)
10:30 - Analytical and numerical modelling of metastructures I

Session chairperson(s): Alessio Monti

10:30 - 11:00 - Perspectives on Huygens’ Metasurfaces for Antenna Beamforming Invited oral [Show abstract]
  • George Eleftheriades, University of Toronto, Canada
  • Vasileios Ataloglou, University of Toronto, Canada
  • Ayman Dorrah, University of Toronto, Canada
In this paper some perspectives on Huygens’ metasurfaces for antenna beamforming are described. Both paired, as well as, single metasurface approaches are described for beamshaping of elementary feeding sources in close proximity. Such metasurfaces are capable of controlling the far-zone radiation patterns of these feeding sources, including the shape of the beams and their sidelobe levels.
11:00 - 11:30 - Validation of the Homogenized Impedance Model for Modulated Metasurface Antennas Invited oral [Show abstract]
  • Enrica Martini, University of Siena, Italy
  • Francesco Caminita, Wave Up, Italy
  • Stefano Maci, University of Siena, Italy
This paper presents a validation of the accuracy of the homogenized impedance model for the description of periodically modulated patch-type metasurfaces. The validation is done through comparison of predicted propagation and attenuation constant and current distribution with results from a full wave solver.
11:30 - 11:45 - A Discontinuous Galerkin Time Domain Solver with Generalized Dispersion Model and its Application to the Analysis of Thin Pixelized Optical Metasurfaces Oral [Show abstract]
  • Wending Mai, Penn State University, USA
  • Sawyer Campbell, Penn State University, USA
  • Pingjuan Werner, Penn State University, USA
  • Yifan Chen, University of Electronic Science and Technology of China, China
  • Douglas Werner, Penn State University, USA
In order to efficiently analyze planar photonic devices, we propose a discontinuous Galerkin time domain (DGTD) method with a generalized dispersive material (GDM) model. By integrating the GDM model into a full-wave DGTD formulation, we develop a general framework that includes a universal model for the analysis of arbitrary dispersive materials. As an example application, we utilize the new DGTD-GDM solver to analyze the response of a thin pixelized metasurface. The metasurface’s optical responses are computed and compared to results obtained using CST, which provides validation of the efficiency improvement as well as accuracy of the proposed algorithm.
11:45 - 12:00 - Omega Bianisotropic Metasurfaces as Huygens' Metasurfaces with Anti-Reflective Coatings Oral [Show abstract]
  • Sherman Marcus, Technion - Israel Instute of Technology, Israel
  • Ariel Epstein, Technion - Israel Institute of Technology, Israel
Omega bianisotropic metasurfaces (OBMS) are capable of producing perfect wide angle anomalous refraction, a feat previously impossible with Huygens' metasurfaces (HMS). Using a geometrical optics model, it is shown that an HMS with an anti-reflective coating can produce the same perfectly refracted field as the OBMS. A realistic design for such a coating is presented for use with a Fabry-Perot HMS. Full-wave calculations not only validate this combination as a new approach for attaining perfect anomalous refraction, but also demonstrate improved angular response.
12:00 - 12:15 - Investigation of the Combined Frequency and Angular Dependencies of Resonances in a Metagrating Using a Waveguide Model Oral [Show abstract]
  • Abdulaziz Haddab, Public Authority for Applied Education and Training , Kuwait
  • Edward Kuester, University of Colorado at Boulder, United States
The frequency and incidence-angle dependence of a metagrating consisting of an array of dielectric-loaded slots in a thick perfectly conducting screen is investigated using an analytical method based on a rectangular waveguide model. This model makes experimental validation much simpler than attempting to approximate an infinitely extended array for measurements. In this paper, we study the effect of air gaps in the dielectric loading on the positions and amplitudes of transmission resonances.
12:15 - 12:30 - Retrieval of the Constitutive Parameters and Dispersion Relation of Glide-Symmetric Metamaterials via the Multimodal Transfer Matrix Method Oral [Show abstract]
  • Ana C. Escobar, Universidad Nacional de Colombia, Colombia
  • Juan P. del Risco, Universidad Sergio Arboleda, Colombia
  • Oscar Quevedo-Teruel, Royal Institute of Technology, Sweden
  • Francisco Mesa, Universidad de Sevilla, Spain
  • Juan D. Baena, Universidad Nacional de Colombia, Colombia
We have implemented a method to retrieve the dispersion relation and the effective material constitutive parameters of a densely arranged periodic structure by solving an eigenvalue problem associated with the multimodal transfer matrix of the corresponding unit cell. The material parameters and the dispersion relation of a metasurface made of glide-symmetric square patches are here obtained with this method.
10:30 - Physics of complex electromagnetic materials I

Session chairperson(s): Mirko Barbuto

10:30 - 11:00 - A Metamaterial-inspired Solution to the RF Blackout Problem Associated with Re-entry and Hypersonic Vehicles Invited oral [Show abstract]
  • Bruce Webb, University of Arizona, United States
  • Richard Ziolkowski, University of Technology Sydney, Australia
A metamaterial-inspired solution to the RF blackout problem that occurs when plasma shrouds form around high-speed vehicles traveling through the atmosphere is reported. Antenna simulations demonstrate significant transmissions into free space beyond the ENG plasma layer facilitated by the pass-band formed by matching a tunable MNG metasurface to it.
11:00 - 11:15 - Delay Time of Microwaves Performing Lévy Flights in 1D Complex Media Oral [Show abstract]
  • Luis Razo-López, Universitè Côte d’Azur, CNRS, Institut de Physique de Nice, France
  • Antonio Fernández-Marı́n, TecNM-Tehuacán, Mexico
  • Antonio Méndez-Bermúdez, Instituto de Fı́sica, Benemérita Universidad Autónoma de Puebla, Mexico
  • José Sánchez-Dehesa, Universitat Politècnica de València, Spain
  • Victor Gopar, Universidad de Zaragoza, Spain
The amount of time that waves spend inside random media is an issue of funda- mental and practical importance. In canonical disordered systems where Anderson localization of waves takes place, this problem has been studied via the time delay. We experimentally and theoretically study the time delay in 1D random media with the possibility that waves perform Lévy flights, which leads to anomalous localization. We show that a wide class of disorder–Lévy disorder–leads to strong random fluctuations of the delay time; nevertheless, the tail of the distribution and the average of the delay time are insensitive to Lévy flights. Our results reveal a universal character of wave propagation that goes beyond standard Brownian wave-diffusion.
11:15 - 11:30 - Complex Frequency Excitation Enabling Perfect Matching of Reactive-Loaded Transmission Lines Oral [Show abstract]
  • Angelica Viola Marini, Università degli Studi Roma Tre, Italy
  • Davide Ramaccia, Università degli Studi Roma Tre, Italy
  • Alessandro Toscano, Università degli Studi Roma Tre, Italy
  • Filiberto Bilotti, Università degli Studi Roma Tre, Italy
In lossless transmission lines terminated on purely reactive loads reflections cannot be avoided, due to the significative impedance mismatch between the real characteristic impedance of the transmission line and the imaginary impedance of the load. Several techniques have been proposed to achieve matching, and all of them are based on the introduction of a resistive lumped element at the end of the line to obtain the power dissipation required to achieve zero reflection. In this contribution, we show a way to achieve the perfect matching condition for purely reactive loads by exploiting the properties of complex frequency excitation, i.e. a signal having a peculiar temporal shape. The proposed solution does not involve dissipation, since the load is purely reactive and energy is stored in the load as long as the complex frequency excitation condition is satisfied, giving rise to an interesting singularity in the transient regime, also known as virtual absorption. Then, the stored energy leaks out the load as soon as the applied excitation varies or stops.
11:30 - 11:45 - Double Imaging by a Periodic Bi-Fold Transformation Medium Oral [Show abstract]
  • Yuma Takano, Osaka University, Japan
  • Atsushi Sanada, Osaka University, Japan
In this paper, double imaging by a periodic bi-fold transformation medium is presented. It is shown that a periodic array of axisymmetric isovolumetric coordinate transformation metamaterials has a double imaging with different angles of sight ±θ due to peculiar refractions on the surface of the medium. The condition for the double imaging is presented and the double imaging operations are confirmed based on ray tracing and full-wave simulations.
11:45 - 12:00 - In-plane Driving of Anapole Resonances in Silicon Disks at Telecom Wavelengths Oral [Show abstract]
  • Alejandro Martinez, Universitat Politecnica de Valencia, Spain
  • Evelyn Díaz-Escobar, Universitat Politecnica de Valencia, Spain
  • Elena Pinilla-Cienfuegos, Universitat Politecnica de Valencia, Spain
  • Thomas Bauer, Delft University of Technology, The Netherlands
  • Ángela Barreda, Friedrich Schiller University Jena, Germany
  • Amadeu Griol, Universitat Politecnica de Valencia, Spain
  • L. Kuipers, Delft University of Technology, The Netherlands
Anapole resonances in high-index dielectric nanoparticles arise from the destructive interference between electric and toroidal dipole moments. So far, this mode interference has been solely observed using normal incidence free-space radiation. Here we show that anapole resonances can also arise in silicon disks being excited by an in-plane oriented waveguide. We provide both far-field and near-field measurements at telecom wavelengths which, in good agreement with numerical simulations, show the expected signatures of an anapole resonance. This work paves the way towards the use of the anapole resonances in on-chip silicon photonics.
12:00 - 12:15 - Magnetoquasistatic Resonances of Small Dielectric Objects Oral [Show abstract]
  • Carlo Forestiere, University of Naples, Italy
  • Giovanni Miano, University of Naples Federico II, Italy
  • Mariano Pascale, University of Naples Federico II, Italy
  • Guglielmo Rubinacci, University of Naples Federico II, Italy
  • Antonello Tamburrino, Universita` di Cassino e del Lazio Meridionale, Cassino, Italy, Italy
  • Roberto Tricarico, ICFO Institut de Cie`ncies Foto`niques, Spain
  • Salvatore Ventre, Universita` di Cassino e del Lazio Meridionale, Cassino, Italy, Italy
A small dielectric object with positive permittivity may resonate when the free-space wavelength is large in comparison with the object dimensions if the permittivity is sufficiently high. We show that these resonances are described by the magnetoquasistatic approximation of the Maxwell’s equations.
12:15 - 12:45 - Non-Hermitian Phase Transitions in Active Many-Body Systems Invited oral [Show abstract]
  • Vincenzo Vitelli, University of Chicago, USA
<p> While wave propagation in non-reciprocal media has recently been under intense study, less is known about the consequences of non-reciprocity on the collective behavior of many-body systems. In this talk, we discuss how non-reciprocity leads to time-dependent collective phases where spontaneously broken symmetries are dynamically restored. The resulting phase transitions are controlled by spectral singularities called exceptional points. We describe the emergence of these phases using insights from bifurcation theory and non-Hermitian quantum mechanics. Our approach captures non-reciprocal generalizations of three archetypal classes of self-organization out of equilibrium: synchronization, flocking and pattern formation. Collective phenomena in these non-reciprocal systems range from active time-(quasi)crystals to exceptional-point enforced pattern-formation and hysteresis. Our work paves the way towards a general theory of critical phenomena in non-reciprocal matter.</p>
10:30 - Nonreciprocal and topological metamaterials I

Session chairperson(s): Emanuele Galiffi

10:30 - 11:00 - Gyromagnetic Topological Photonic Crystals Invited oral [Show abstract]
  • Baile Zhang, Nanyang Technological University, Singapore
The field of topological photonics started ten years ago with the first photonic topological insulator realized in a gyromagnetic photonic crystal. While the field is progressing enormously, the development in the gyromagnetic topological photonic crystals is quite limited. Here I will introduce some new configurations in gyromagnetic topological photonic crystals.
11:00 - 11:30 - Realizing Topological Phenomena Using Transmission Line Networks Invited oral [Show abstract]
  • C.T. Chan, HKUST/Physics, Hong Kong
We will show that the transmission line network is a versatile platform that can demonstrate new physics notions including topological effects due to orbital angular momentum, the effect of disorder on topological states and new topological phases due to non-Abelian band topologies.
11:30 - 11:45 - A Topolectrical Higher-order Chern Insulator Oral [Show abstract]
  • Xiang Ni, City University of New York, United States
  • Zhicheng Xiao, University of Texas at Austin, United States
  • Alexander Khanikaev, City University of New York, United States
  • Andrea Alu, City University of New York, United States
We propose a scheme to realize a higher-order Chern insulator in an electrical circuit. By utilizing basic circuit elements synthesizing complex hoppings between sites of the lattice, we observe multiple topological phases of the three-dimensional circuit array, including higher-order Chern number and crystalline topological phase. In addition to nonreciprocal propagation of topological chiral hinge states, we find that these chiral states do not flow into the hinge opposite to the excitation, opening interesting opportunities for multiplexing.
11:45 - 12:00 - Broadband LDOS and Second-Harmonic Generation Enhancement in Nonreciprocal Hotspots Oral [Show abstract]
  • Sander Mann, CUNY ASRC, USA
  • Ahmed Mekkawy, CUNY ASRC, USA
  • Andrea Alù, CUNY ASRC, USA
Put your abstract hereWe discuss nonreciprocal hotspots for photonic applications, which are not subject to the same trade-off as reciprocal cavities, thereby providing unique and exciting opportunities. In particular, we demonstrate how these hotspots provide extremely large and broadband LDOS and second-harmonic generation enhancements.
12:00 - 12:15 - Broadband Enhanced Nonlinear Harmonic Generation in Terminated Unidirectional Plasmonic Waveguides Oral [Show abstract]
  • Ali Hassani , Cornell University, USA
  • Boyuan Jin, University of Nebraska-Lincoln, USA
  • Christos Argyropoulos, University of Nebraska-Lincoln, USA
  • Francesco Monticone, Cornell University, USA
In this work, we discuss the application of terminated one-way plasmonic waveguides in enhancing nonlinear effects by orders of magnitude over broad bandwidths. We first theoretically demonstrate that remarkable levels of electric field enhancement (field hot-spots) can be achieved when the propagation path of one-way magneto-plasmons is suitably terminated. Then, by investigating the nonlinear, nonlocal, non-Hermitian and dispersive behavior of a relevant example of terminated plasmonic waveguide, we show that the presence of these giant broadband field hot-spots leads to a significant boosting of nonlinear interactions, exemplified by an improvement of several orders of magnitude in the third-harmonic-generation efficiency
12:15 - 12:30 - Broadband Slow Light In Topologically Protected Unidirectional Waveguides Oral [Show abstract]
  • Sander Mann, CUNY ASRC, USA
  • Andrea Alù, CUNY ASRC, USA
We demonstrate that broadband slow light can be achieved over the entire topological bandgap by periodically loading a protected unidirectional edge state with low-Q resonances. As a result of the broadband slow light, the dispersion folds around the Brillouin zone multiple times. We discuss implementations and limitations in (non)reciprocal systems.
12:30 - 13:00 - Far- and Near-Field Imaging of Higher-Order Topological Photonic States at Optical Frequencies Invited oral [Show abstract]
  • Anton Vakulenko, City College of the City University of New York, USA
  • Svetlana Kiriushechkina, City College of the City University of New York, USA
  • Mingsong Wang, City University of New York, USA
  • Mengyao Li, City College of the City University of New York, USA
  • Dmitry Zhirihin, City College of the City University of New York, USA
  • Xiang Ni, City College of the City University of New York, USA
  • Sriram Guddala, City College of the City University of New York, USA
  • Dmitriy Korobkin, City College of the City University of New York, USA
  • Andrea Alù, Advanced Science Research Center, USA
  • Alexander B. Khanikaev, City College of the City University of New York, USA
Higher-order topological insulators (HOTIs) represent a new type of topological systems supporting robust boundary states localized over boundaries two or more dimensions lower than the dimensionality of the system itself. Several photonic HOTI geometries have been recently proposed and experimentally studied, highlighting the possibility of trapping boundary states in lower dimensions and their topological resilience. Interestingly, photonic HOTIs can possess a richer physics than their original condensed matter counterpart, supporting conventional HOTI states based on tight-binding coupling, and a new type of topological HOTI states enabled by long-range interactions. Here, we propose a new mechanism to establish all-dielectric infrared HOTI metasurfaces exhibiting both types of HOTI states, supported by a topological transition accompanied by the emergence of topological Wannier-type polarization. We performed far-field and two types of near-field experimental studies (i) the solid immersion spectroscopy and (ii) near-field imaging using s-SNOM to directly observe the topological transition and the emergence of HOTI states of two types. The studies revealed the topological transition, the presence of topological modes at the boundaries, and confirmed the existence of a new type of corner states enabled by long-range interactions, ubiquitous in photonic systems. The proposed all-dielectric metasurface with multiple topological states confined in one and zero dimensions paves the way towards novel applications of topological photonics for robust trapping and guiding of light. Our results may enable future designs of topological metasurfaces and lay the foundation for a new active nanophotonic platform for resilient control of optical radiation where the modes of different order can be actively coupled or converted into one another.
10:30 - Plasmonics I

Session chairperson(s): Viktoriia Rutckaia

10:30 - 11:00 - Metasurface-Enabled Generation of Single Photons with Engineered Wavefronts and Polarizations Invited oral [Show abstract]
  • Sergey Bozhevolnyi, SDU Nano Optics, University of Southern Denmark, Denmark
A conceptually novel approach to generation of single photons with engineered wavefronts and polarizations is presented, which entails nonradiative coupling of quantum emitters to cylindrically diverging surface plasmon polaritons that are subsequently outcoupled by design metasurfaces into collimated streams of photons in a desired polarization state.
11:00 - 11:15 - Aluminum-based Hybrid Gratings for Infrared Spectral Emissivity Design Oral [Show abstract]
  • Romil Audhkhasi, University of Southern California, USA
  • Michelle Povinelli, University of Southern California, USA
We use aluminum gratings to design emitters with predefined spectral response in the infrared. We create a reference library to investigate the relationship between the grating design parameters and their spectral properties. Next, we develop a search algorithm based on minimization of errors to select gratings from this library corresponding to emission peaks with desired spectral attributes. Finally, we discuss an approach for designing hybrid structures using these gratings to generate a few predefined target spectra.
11:15 - 11:30 - Transverse Magneto-Optical Effect in Asymmetric Plasmonic Nanostructures Oral [Show abstract]
  • Olga Borovkova, Russian Quantum center, Russia
  • Hisham Hashim, Tanta University, Egypt
  • Mikhail A. Kozhaev, Russian Quantum center, Russia
  • Andrey N. Kalish, Russian Quantum center, Russia
  • Sarkis A. Dagesyan, Lomonosov Moscow State University, Russia
  • Alexander N. Shaposhnikov, Research Center for Functional Materials and Nanotechnologies, Russia
  • Vladimir N. Berzhansky, Institute of Physics and Technology, V.I. Vernadsky Crimean Federal University, Russia
  • Anatoly K. Zvezdin, Russian Quantum center, Russia
  • Larissa V. Panina, National University of Science and Technology (MISIS), Russia
  • Vladimir I. Belotelov, Russian Quantum center, Russia
The transverse magneto-optical effect in transmission is addressed in plasmonic nanostructures with three different kinds of spatial symmetry breaking. The features of the transverse magnetophotonic effect in transmission in each of the asymmetric magnetoplasmonic nanostructures are reported.
11:30 - 11:45 - Modal Analysis of 2D Broadband Plasmonic Resonators Oral [Show abstract]
  • Mariano Pascale, Università degli studi di Napoli Federico II, Italy
  • Sander Mann, City University of New York, Advanced Science Research Center, United States
  • Carlo Forestiere, Università degli studi di Napoli Federico II, Italy
  • Andrea Alù, City University of New York, Advanced Science Research Center, United States
The enhancement of light-matter interaction is usually achieved through resonant mechanisms, affected by a trade-off between the field enhancement factor and bandwidth. Several plasmonic devices, featuring geometrical singularities, have been proposed for efficient light harvesting over a wide part of the visible spectrum, therefore overcoming the fundamental competition between bandwidth and field enhancement in small footprints. In this work, we propose an analytical approach for the analysis of such configurations, based on a field modal expansion. We pinpoint the existence of an accumulation point in the spectrum of the plasmonic operator governing the electromagnetic scattering process and investigate the time-dynamics of two coupled parallel infinite cylinders. Finally, based on the obtained insight, we place the sensitivity to fabrication disorder of such singular structures in the context of the Chu limit.
11:45 - 12:00 - Enhanced White-Light Photoluminescence in Hybrid Metal-Dielectric Nanosponge. Oral [Show abstract]
  • Dmitry Zuev, ITMO University, Russia
  • Artem Larin, ITMO University, Russia
Creation of compact and efficient light sources is one of the fast-developing directions in nanophotonics. Here, we study hybrid nanosystem representing plasmonic nanosponge (Au) which pores are filled by high refractive index semiconductor (Si). We show experimentally that system possess broadband white light emission under irradiation by femtosecond laser pulses. Numerical studies demonstrate that in the case of three-photon excitation such system provides broadband enhancement in the region of photoluminescence. We believe hybrid metal-dielectric nanosponges can be used as universal white-light source for sensing, lab on a chip devices, etc.
12:00 - 12:15 - Thermal Effect in Plasmon Assisted Photocatalyst: A Parametric Study Oral [Show abstract]
  • Ieng-Wai Un, School of Electrical and Computer Engineering, Ben-Gurion University of the Negev, Israel, Israel
  • Yonatan Sivan, School of Electrical and Computer Engineering, Ben-Gurion University of the Negev, Israel, Israel
We study the parametric dependence of the temperature distribution in plasmon-assisted photocatalysts. Our results provide a better understanding of thermal effects in conventional photocatalytic experiments and other applications that rely on heat generation from a large number of particles.
12:15 - 12:30 - Manipulating Surface Plasmons Propagation Using Ultra-Compact and Non-Dielectric Designs Oral [Show abstract]
  • Joseph Riley, School of Engineering, Newcastle University, United Kingdom
  • Noel Healy, School of Mathematics Statistics and Physics, Newcastle University, United Kingdom
  • Victor Pacheco-Peña, School of Mathematics Statistics and Physics, Newcastle University, United Kingdom
We present a method capable of manipulating and controlling the propagation of surface plasmons using plasmonic structures composed only of metals. As an example of our technique, we design, evaluate and demonstrate a plano-convex lens with the ability to focus the incident surface plasmons onto a single focal spot.
12:30 - 13:00 - Designer Structured Light with Metasurfaces Invited oral [Show abstract]
  • Federico Capasso, Harvard University, USA
Metasurfaces are a powerful tool to design arbitrary vector beams. I will discuss recent work on spin to total orbital angular momentum converters, high purity OAM lasing and structured light generation along the propagation direction.
10:30 - Metasurfaces and absorbers

Session chairperson(s): You Zhou

10:30 - 11:00 - Compound Metaoptics: Achieving Complex Electromagnetic Transformations with Cascaded Metasurfaces Invited oral [Show abstract]
  • Anthony Grbic, University of Michigan, USA
  • Faris Alsolamy, University of Michigan, USA
  • Brian Raeker, University of Michigan, USA
  • Steve Young, University of Michigan, USA
  • Jordan Budhu, University of Michigan, USA
This talk will describe recent advances in compound metaoptics: devices based on multiple metasurfaces arranged along an axis. The additional degrees of freedom afforded by compound metaoptics enable electromagnetic responses that are difficult or impossible to achieve with a single metasurface. Analysis methods will be presented that rigorously account for and exploit the interactions between tightly coupled metasurfaces and metasurface elements. In addition, several metaoptic devices will be described exhibiting a wide range of wavefront and spectral control functions. These will include broadband, multiband, and multifunctional polarization converters; multiband metasurface-based reflectarray antennas; paired metasurfaces that exhibit reflectionless and lossless transformation of a wavefront's amplitude and phase distributions; and tightly coupled metasurface stacks that allow extreme mode conversion and aperture synthesis.
11:00 - 11:30 - Virtual Absorption/Gain through Time Modulation Invited oral [Show abstract]
  • Dimitrios Sounas, Wayne State University, USA
Virtual perfect absorption is the effect in which the reflection from a reactive lossless load is canceled due to appropriate shaping of the impinging signal or time-modulation of the load, resulting in transfer of the signal to the load in the form of stored energy. As a result, the load appears lossy, although it does not contain any lossy elements. Here, we present a simple circuit based on a time-modulated inductor and capacitor that exhibits a real effective impedance, either positive or negative, thereby providing virtual loss or gain. We also show how the same circuit can also realize time-varying positive/negative effective impedances. Quite importantly, the required modulation is adiabatic, making it easier to realize than other approaches. We expect that these results will be useful in the design of parity-time symmetric systems and photonics topological insulators.
11:30 - 11:45 - Multifunctional Single-Layer Metasurface for Electromagnetic Wave Manipulations Oral [Show abstract]
  • Ihar Faniayeu, University of Gothenburg, Sweden
  • Ivan Fanyaev, Francisk Skorina Gomel State University, Belarus
  • Segrei Khakhomov, Francisk Skorina Gomel State University, Belarus
  • Igor Semchenko, Francisk Skorina Gomel State University, Belarus
We report a design of single-layer metasurface with multifunctional control of electromagnetic waves at different frequencies in the microwave range. The metasurface performs three main functionalities as a total absorption and polarization conversions in the reflection and transmission regimes while being fully transparent away from the resonance frequencies. The proposed multifunctional metasurface exhibits a great performance and might be a good candidate for the microwave filtering and antenna applications.
11:45 - 12:00 - Mode Conversion in Cylindrical Waveguides Using Metasurfaces Oral [Show abstract]
  • Faris Alsolamy, University of Michigan Ann Arbor, USA
  • Anthony Grbic, University of Michigan Ann Arbor, USA
A general method to convert between azimuthally-invariant TM0n cylindrical waveguide modes using metasurfaces is presented. Mode conversion is achieved by a metasurface comprising cascaded electric impedance sheets that vary radially. The metasurface is described by a modal scattering matrix that relates the incident and reflected modes on both sides of the metasurface. The sheets’ impedance profiles of the metasurface are optimized to realize stipulated modal scattering matrix entries. As an example, a mode splitter that divides the power of an incident TM01 mode evenly between TM01 and TM02 modes is reported at 10 GHz. The performance of the mode splitter is verified using a commercial electromagnetic field solver.
12:00 - 12:15 - Omnidirectional, Frequency Selective Metasurface Absorber based on Quasi-Bound States in the Continuum Oral [Show abstract]
  • Kunal Shastri, Cornell University, USA
  • Francesco Monticone, Cornell University, USA
In this work we show that there is a tradeoff between the maximum absorbed power and the angular dependence for a metasurface absorber. Using spherical nanoparticles supporting embedded eigenstates, we present a metasurface that minimizes the angular dependence of the absorption peak and simultaneously realizes an ultra-narrow absorption linewidth
12:15 - 12:30 - Broadband Absorption Limits for Ultrathin Solar Cells Oral [Show abstract]
  • Aobo Chen, Cornell University, USA
  • Francesco Monticone, Cornell University, USA
We study Bode-Fano bounds on the maximum attainable solar power absorption, over the whole solar spectrum, for ultrathin solar cells made of different materials and with antireflection coatings of arbitrary complexity.
12:30 - 14:00 - Lunch Break (Monday)
14:00 - 15:30 - Oral Sessions (Monday Afternoon 1)
14:00 - Chiral and Bianisotropic media

Session chairperson(s): Seunghwi Kim

14:00 - 14:30 - Scattering Properties of Parity-Time Symmetric Chiral Metamaterials Invited oral [Show abstract]
  • Maria Kafesaki, Foundation for Research and Technology Hellas and University of Crete, Greece
  • Ioannis Katsantonis, Foundation for Research and Technology Hellas and University of Crete, Greece
  • Sotiris Droulias, Foundation for Research and Technology Hellas and University of Crete, Greece
  • Elefterios Economou, Foundation for Research and Technology Hellas and University of Crete, Greece
  • Costas Soukoulis, Foundation for Research and Technology Hellas and Iowa State University, USA
We show that combining PT-symmetry and chirality in the same metamaterial system one can achieve a variety of novel propagation and scattering effects. These include mixed PT-related phases, multiple exceptional points, asymmetric reflection and transmission, asymmetric transmitted wave ellipticity and optical activity, and others. The appearance of all these uncommon features can be highly controlled by either the system chirality or, dynamically, by the angle of incidence, resulting to a variety of possibilities in all applications targeting electromagnetic wave polarization control.
14:30 - 14:45 - Towards Integrated Chiroptical Applications Oral [Show abstract]
  • J. Enrique Vázquez-Lozano, Universitat Politècnica de Valencia (NTC-UPV), Spain
  • Alejandro Martı́nez, Universitat Politècnica de Valencia (NTC-UPV), Spain
Optical techniques to check the chiral response of either chemical (bio)molecules or artificial nanostructures usually relies upon free-space illumination and detection. Here, we propose chiral characterization via light-waves in an integrated approach. The viability of this approach is numerically tested using a metallic nano-helix as a chiral probe.
14:45 - 15:00 - Demonstration of the Relation Between Co- and Cross-Polarizabilities Using a Multipole Expansion of the Electromotive Force for Planar Bianisotropic Scatterers Oral [Show abstract]
  • Ana C. Escobar, Universidad Nacional de Colombia, Colombia
  • Juan D. Baena, Universidad Nacional de Colombia, Colombia
For many small scatterers $alpha_{ee} alpha{mm} = alpha_{me}alpha_{em}$. However, it is possible to find others that strongly violate this rule. By using a multiple expansion on the electromotive force of an equivalent circuit equation obtained via the complex Poynting’s theorem, here we demonstrate that the rule is only valid when the expansion can be truncated at the dipole moments.
15:00 - 15:15 - A Low-Reflection Absorptive Metasurface for Mid-IR Wavelengths Oral [Show abstract]
  • Ihar Faniayeu, University of Gothenburg, Sweden
  • Vygantas Mizeikis, Shizuoka University, Japan
  • Alexander Dmitriev, University of Gothenburg, Sweden
We report a design of an optical metasurface that selectively absorbs impinging electromagnetic waves in the desired wavelength while being fully transparent away from the resonance range. The proposed absorber consists of three-dimensional helical resonators that enable full control of light absorption due to the manipulation of the induced electric and magnetic dipole moments at the resonance. Full-wave simulations confirm the effectiveness of the proposed concept in the mid-infrared spectral range.
15:15 - 15:30 - Geometrical Optics Solution for Periodic Multilayer Anisotropic Slab Scattering Oral [Show abstract]
  • Manushanker Balasubramanian, The Pennsylvania State University, USA
  • Sawyer D Campbell, The Pennsylvania State University, USA
  • Pingjuan L Werner, The Pennsylvania State University, USA
  • Douglas H Werner, The Pennsylvania State University, USA
In this paper, a Geometrical Optics (GO) solution for electromagnetic scattering from a periodic multilayer anisotropic slab is presented. An approach based on the Transfer Matrix Method (TMM) is used to determine effective slab reflection and transmission coefficients. Numerical results for various scattering problems showing excellent agreement with reference solutions are provided.
14:00 - Physics of complex electromagnetic materials II

Session chairperson(s): Emanuele Galiffi

14:00 - 14:30 - Quantum Electrodynamics in Metamaterial Waveguides Invited oral [Show abstract]
  • Iñigo Liberal, Universidad Publica de Navarra, Spain
Metamaterial waveguides are known to provide additional degrees of freedom in dispersion engineering, thus enabling a finer control over the spectral response of microwave and optical components. In our presentation, we will review how similar concepts can be applied to the field of waveguide quantum electrodynamics (QED), including the generation of nonclassical light states, multi-qubit entanglement generation, and engineering many-body physics.
14:30 - 15:00 - Metamaterials, Gyroscopes, and Two Century-Old problems in Number Theory Invited oral [Show abstract]
  • Ben Z. Steinberg, Tel-Aviv University, Israel
  • Ido Kazma, Tel-Aviv University, Israel
We discuss the electrodynamics of slowly rotating metamaterials as observed in their rest frame of reference, and present a corresponding first order polarizability theory. A formulation governing the response of an arbitrary array of scatterers to excitation under rotation is provided and used to explore the rotation footprint properties. The metamaterial sensitivity to rotation can be intimately related to two century-old problems in number theory: the no-three-in-line problem, and the Heilbronn triangle problem. New arrays, base on Erd˝os solution to the former, are proposed.
15:00 - 15:15 - Anderson Localization of Light in 3D Clusters of High-Index Dielectric Spheres Investigated by Full-Wave Optical Simulations Oral [Show abstract]
  • Theodosios Karamanos, Karlsruhe Institute of Technology, Germany
  • Carsten Rockstuhl, Karlsruhe Institute of Technology, Germany
A methodology to investigate 3D Anderson localization of light in large-scale clusters made from high index dielectric spheres is proposed. First, sets of cylindrical slabs with a larger diameter are constructed consisting of dense arrangements of micron-sized GaAs spheres. Second, the full-wave optical problem is solved by means of a T-matrix approach upon illuminating the sample with a Gaussian beam. Light transmission indicates that only classical diffusion occurs and strong localization effects observed in some experiments should be attributed to absorption. The proposed method is an excellent tool to tweak the multipolar response from the spheres to drive the system into a regime where localization is observed, thus providing clear indications for future experiments.
15:15 - 15:30 - Tunable and Robust Long-range Coherent Dipole Interactions Mediated by Weyl Bound States Oral [Show abstract]
  • Iñaki García-Elcano, Universidad Autónoma de Madrid, Spain
  • Alejandro González-Tudela, Instituto de Física Fundamental IFF-CSIC, Spain
  • Jorge Bravo-Abad, Universidad Autónoma de Madrid, Spain
We investigate the quantum optical behavior of quantum emitters coupled to a Weyl-like photonic environment. For the single emitter case, we report on the formation of a photon-atom bound state featuring a tunable power-law confinement. When two emitters are considered, the emergent bound state can mediate robust long-range coherent interactions.
14:00 - Metasurfaces I

Session chairperson(s): Adam Overvig

14:00 - 14:30 - Metasurfaces 3.0: a Key Enabling Technology for the Development of beyond-5G Communication Systems Invited oral [Show abstract]
  • Mirko Barbuto, “Niccolò Cusano” University, Italy
  • Angelica Viola Marini, ROMA TRE University, Italy
  • Alessio Monti, “Niccolò Cusano” University, Italy
  • Davide Ramaccia, ROMA TRE University, Italy
  • Stefano Vellucci, University of Trento, Italy
  • Alessandro Toscano, ROMA TRE University, Italy
  • Filiberto Bilotti, ROMA TRE University, Italy
In the last two decades, the concept of metasurfaces has evolved, leading, nowadays, to unprecedented possibilities. The first generation of metasurfaces was based on regular homogeneous periodic structures. This 2D version of volumetric metamaterials had a dramatic impact in many application fields, ranging from radio up to optical frequencies. Following the evolution path of the metasurface concept, the second generation of metasurfaces was based on inhomogeneous structures characterized by quasi-periodical or gradient-like arrangements. The spatial modulation of the metasurface properties allowed enhancing the capabilities, thanks to the higher number of degrees of freedom available. Finally, the third generation of metasurfaces consists of thin patterned structures whose properties can be controlled in both space and time. This possibility, enabled by different control mechanisms (e.g. electronic, optical, thermal, chemical, liquid crystal based, etc.) and boosted by the recent advances in integration and micro-/nano-fabrication technologies, allows conceiving tunable, reconfigurable, and programmable structures that can be used in a variety of applications. In this contribution, after a review of the three generations of metasurfaces and a detailed focus on the current third generation, the potential impact of these structures as a key enabling technology for beyond 5G communication systems will be discussed.
14:30 - 14:45 - Broadband Metasurfaces through First Order Approximation of Surface Impedances Oral [Show abstract]
  • Ashif A. Fathnan, University of New South Wales, Canberra, Australia
  • Andreas E. Olk, IEE S.A., 1, rue de Campus, 7795 Bissen, Luxembourg, Luxembourg
  • David A. Powell, University of New South Wales, Canberra, Australia
We introduce a method of bandwidth enhancement on metasurfaces based on a more insightful analytical approach of LC resonances. In obtaining L and C parameters, we use surface impedance model considering not only a single frequency matching but also its first frequency derivative. We show that broadband anomalous reflection can be obtain with simple geometries involving dipole and inverse dipole structures. We verified our method using experiment in millimeter-wave frequencies and show that the broadband metasurface achieves a significant increase of bandwidth (more than 80\% increase) compared to a single frequency design, with minimum -3dB power is maintained in the desired reflection and maximum -10dB for all other diffraction orders.
14:45 - 15:00 - 3D-printed Metasurfaces of Capped Helices Providing Broadband Negative Mode Index Oral [Show abstract]
  • Pavel Petrov, University of Exeter, United Kingdom
  • Alastair Hibbins, University of Exeter, United Kingdom
  • Nesma Aboulkhair, University of Nottingham, United Kingdom
  • Ehab Saleh, University of Leeds, United Kingdom
  • Roy Sambles, University of Exeter, United Kingdom
Using structures of subwavelength metallic capped helices with both negative electric and magnetic couplings, we demonstrate a broadband negative mode index metasurface. Numerical and experimental results are presented for the structure with negative dispersion bandwidth of 44% compared to the resonant frequency of individual capped helices. Optimisation of such structures in terms of their size, element geometry and operational passband width is demonstrated.
15:00 - 15:15 - Equivalent Surface Impedances for Below-Cutoff Propagation in Circular Waveguides Oral [Show abstract]
  • Christopher Barker, University of Alberta, Canada
  • Ashwin Iyer, University of Alberta, Canada
A relation between a metamaterial (MTM) liner for a circular waveguide and its equivalent surface impedance is made to allow for the replacement of the MTM liner with a metasurface. The equivalent surface impedance is found for a representative MTM-lined waveguide design and below-cutoff backward-wave propagation is predicted.
15:15 - 15:30 - A Reflective Metasurface for Perfect Cylindrical to Planar Wavefront Transformation Oral [Show abstract]
  • Jordan Budhu, University of Michigan, USA
  • Anthony Grbic, University of Michigan, USA
The problem of perfectly transforming an incident cylindrical wave into a reflected plane wave using a reflective metasurface is considered. The metasurface is a subwavelength-patterned metallic cladding that is placed above a ground plane. The subwavelength features of the textured metallic cladding are homogenized and represented as a purely reactive impedance sheet. The homogenization allows the mutual coupling between elements to be modeled efficiently and accurately. An integral equation is constructed which relates the surface impedance to the desired total electric field in the aperture. The integral equation is solved via the method of moments to find the required sheet impedance of the patterned metallic cladding. The resulting impedance is, in general, complex indicating the need for lossy and/or active elements, which is generally undesired. Here, we use an optimization strategy to remove the real part of the sheet impedance, while still achieving the field transformation of the complex sheet. In other words, a purely reactive sheet is maintained with no need for loss and/or gain. Hence, we show that shaping of amplitude and phase in the radiative near field can be achieved using a single, fully passive, electric impedance sheet.
14:00 - Metamaterials with extreme parameters I

Session chairperson(s): Michele Cotrufo

14:00 - 14:30 - Coherent Retroreflectors for Realization of Bound States in Waveguides Extended oral [Show abstract]
  • Grigorii Ptitcyn, Aalto University, Finland
  • Francisco Cuesta, Aalto University, Finland
  • Sergei Tretyakov, Aalto University, Finland
In this talk, we present our recent results on single-sheet metasurfaces which act as retroreflectors when illuminated from both sides by two coherent plane waves. We call these sheets ``coherent retroreflectors''. In particular, we discuss an application of these metasurfaces for realization of a bound state in a waveguide.
14:30 - 15:00 - Inherent Plasmonic Skyrmion Comb with Topological Robustness and Extremely Subwavelength Footprint Extended oral [Show abstract]
  • Zi-Lan Deng, City University of New York, USA
  • Tan Shi, Jinan University, China
  • Alex Krasnok, City University of New York, USA
  • Xiangping Li, Jinan University, China
  • Andrea Alù, City University of New York, USA
We explore meta-structures supporting comb-like resonances with skyrmion features, highly desirable for compact, stable, and robust information processing. The skyrmion combs are originated from inherently localized plasmon resonances. The demonstrated topological properties open exciting avenues towards dynamic data storage, near-field communications with simultaneous ultra-compact and topologically robust features.
15:00 - 15:15 - Electromagnetic Response of Ballistic Metamaterials Withdrawn [Show abstract]
  • Evgenii Narimanov, Purdue University, USA
Ballistic metamaterials, metal-dielectric composites with the unit cell size smaller than electron mean free path, represent a new class of composite media with many unique properties, such as hyperbolic response above the plasma frequency. The electromagnetic response of these ballistic metamaterials is controlled by the surface scattering of the free electrons at the metal-dielectric interface.
15:15 - 15:30 - Nonlinear PT-Symmetric Epsilon-Near-Zero Metamaterials to Achieve Strong Self-Induced Nonreciprocal Transmission Oral [Show abstract]
  • Christos Argyropoulos, University of Nebraska-Lincoln, USA
  • Boyuan Jin, University of Nebraska-Lincoln, USA
A pronounced self-induced nonreciprocal transmission is demonstrated due to the enhanced Kerr nonlinear effect in compact epsilon-near-zero media photonically doped with gain and loss defects. The obtained nonlinear parity-time symmetric metamaterial system can achieve almost unitary transmission contrast by operating close to the exceptional point.
14:00 - Special session: Physical Review Symposium I

Session chairperson(s): Andrea Alu

14:00 - 14:30 - Parametric Control of Wave Scattering Invited oral [Show abstract]
  • Ilya Shadrivov, Australian National University, Australia
By using parametrically modulated metasurfaces, we propose and demonstrate an extremely flexible approach for manipulating electromagnetic waves. We show that the metasurfaces with periodically changing parameters can control scattered waves both in frequency and spatial domain.
14:30 - 15:00 - Van der Waals Metamaterials Invited oral [Show abstract]
  • William Dorrell, Harvard University, USA
  • Harris Pirie, Harvard University, USA
  • Minhal Gardezi, Wellesley College, USA
  • Nathan Drucker, Harvard University, USA
  • Jennifer Hoffman, Harvard University, USA
We introduce van der Waals metamaterials to rapidly prototype and screen their quantum counterparts. These layered metamaterials are designed to reshape the flow of ultrasound to mimic electron motion. In particular, we show how to construct analogs of all stacking configurations of bilayer and trilayer graphene through the use of interlayer membranes that emulate van der Waals interactions. By changing the membrane's density and thickness, we can also reach coupling regimes far beyond that of naturally occurring graphene. We anticipate that van der Waals metamaterials can be used to explore, extend, and inform future electronic devices. Furthermore, they allow the transfer of useful electronic behavior to acoustic systems, such as flat bands in magic-angle twisted bilayer graphene, which may aid the development of super-resolution ultrasound imagers.
Media link(s):

See Phys. Rev. B 101, 121103R (2020)

https://doi.org/10.1103/PhysRevB.101.121103

15:00 - 15:30 - Spectral Design of Active Mechanical and Electrical Metamaterials Invited oral [Show abstract]
  • Henrik Ronellenfitsch, Massachusetts Institute of Technology, USA
  • Jorn Dunkel, Massachusetts Institute of Technology, USA
Building on a recently developed linear response optimization framework, we here demonstrate that the spectra of nonlinear active mechanical and electric circuits can be designed similarly to those of linear passive network.
15:30 - 16:00 - Coffee Break (Monday Afternoon)
16:00 - 18:00 - Oral Sessions (Monday Afternoon 2)
16:00 - Analytical and numerical modelling of metastructures II

Session chairperson(s): Nikita Nefedkin

16:00 - 16:30 - On the Calculation of Phase and Attenuation Constants in Periodic Structures Invited oral [Show abstract]
  • Francisco Mesa, Dpt. Applied Physics 1, University of Sevilla, Spain
  • Guido Valerio, Sorbonne Universit'e, CNRS, Lab.,de G'enie Electrique et Electronique de Paris, 75252, Paris, France
  • Oscar Quevedo-Teruel, KTH Royal Institute of Technology, SE-10044 Stockholm, Sweden
In this work, we will present our recent research on the obtaining of the dispersion relation (both the phase shift and the attenuation constant) of the periodic structure from the multi-modal transfer matrix of the unit cell, taking also advantage of the possible higher symmetries that may exist in the unit cell. The non-trivial extension to 2-D periodic structures will also be discussed and complemented with several numerical examples of application.
16:30 - 17:00 - Integral-Equation Based Metasurface Design and Beams Superposition Invited oral [Show abstract]
  • Modeste Bodehou, Université catholique de Louvain, Belgium
  • Christophe Craeye, Université catholique de Louvain, Belgium
Metasurface antennas are artificially engineered surfaces designed to generate a given radiation pattern from excitation specifications. The radiation analysis of electromagnetic surfaces can be rigorously carried out in an integral equation formalism with the Method of Moments (MoM). Recently, a technique based on the MoM has been proposed for the direct synthesis of metasurface antennas. We explain how relying on the integral-equation approach in the design phase allows a good control of the radiation, beyond the capabilities of holographic techniques; we also highlight the way in which the method deals with the non-linear relation between surface impedance and radiation patterns.
17:00 - 17:15 - Broadband Transparent Metasurfaces for Anomalous Refraction Oral [Show abstract]
  • Manuel Londoño, Universidad Nacional de Colombia, Colombia
  • Ana C. Escobar, Universidad Nacional de Colombia, Colombia
  • Juan D. Baena, Universidad Nacional de Colombia, Colombia
In this work a metasurface able to provide anomalous refraction of a plane wave has been proposed. Unlike other designs, our structure is made of just one type of geometry, what makes the design very simple. Besides, since each element is very transparent in a wide range of frequency, at least in the range 0-6 GHz, the whole metasurface is frequency stable. We have found that the simulated structure provide anomalous refraction from 3 to 4 GHz.
17:15 - 17:30 - Design and Optimization of a Shared Aperture Multifunctional Metasurface Antenna Oral [Show abstract]
  • Timothy Sleasman, JHU APL, USA
  • David Shrekenhamer, JHU APL, USA
  • Paul Vichot, JHU APL, USA
  • Stephanie Lashley, JHU APL, USA
<p> A single metasurface is designed which can convert a traveling-wave antenna’s feed wave into a collection of radiation patterns. Multiple holographic patterns are jointly optimized to create a series of steered beams through a switched-feed architecture.</p>
17:30 - 17:45 - IE-GSTC Analysis of Metasurface Cavities and Application to Redirection Cloaking Oral [Show abstract]
  • Mojtaba Dehmollaian, Ecole Polytechnique de Montreal, Canada
  • Christophe Caloz, Katholieke Universiteit (KU) Leuven, Belgium
This paper presents a technique based on combination of Integral Equations (IEs) and Generalized Sheet Transition Conditions (GSTCs) with bianisotropic susceptibility tensors to compute the wave scattering by an arbitrarily-shaped cylindrical metasurface cavity containing impenetrable scatterers. Moreover, it applies this technique to a newly introduced form of cloaking, redirection cloaking that seems more realistic than transformation-electromagnetics cloaking, showing that adequately synthesized gain-less and loss-less susceptibilities can effectively cloak an impenetrable object of arbitrary shape.
17:45 - 18:00 - A Single-Resonator Model for Fano-Like Resonances and Its Applications to Modelling Simple Metasurface Unit Cells Using Multiconductor Transmission-Line Theory Oral [Show abstract]
  • Stuart Barth, N/A, Canada
Equivalent-circuit models of Fano-like resonances have typically included multiple resonators. In this work, it is demonstrated that Fano-like resonances can be realized with one parallel-LC resonator, along with a phase shift, for example as provided by a transmission-line section. An application of this model is provided by investigating a plane wave normally incident on a simple transversely periodic LC-based metasurface, which is modelled using a multiconductor transmission-line with an embedded LC resonator. Investigation of the model reveals that the bandwidth of the resulting Fano-like resonance may be controlled with the ratio of the L and C values.
18:00 - 18:30 - Scattering Matrices as a Paradigm for Artificial Materials based Devices Synthesis Invited oral [Show abstract]
  • Roberta Palmeri, Università Mediterranea of Reggio Calabria, Italy
  • Tommaso Isernia, Università Mediterranea of Reggio Calabria, Italy
In this contribution we study the feasibility of a novel approach to design artificial materials based devices. In particular, the scattering matrices method originally introduced for analysis problems is conveniently turned into a tool for synthesis and design. In particular, two design strategies are proposed and commented. A first assessment regarding PBG based devices is performed through the design of a waveguide having enhanced performances.
16:00 - Physics of complex electromagnetic materials III

Session chairperson(s): Huanan Li

16:00 - 16:15 - Space-Time Non-Separability of Complex Electromagnetic Fields Generated by Metasurfaces Oral [Show abstract]
  • Yijie Shen, Optoelectronics Research Centre & Centre for Photonic Metamaterials, University of Southampton, , United Kingdom
  • Apostolos Zdagkas, Optoelectronics Research Centre & Centre for Photonic Metamaterials, University of Southampton, , United Kingdom
  • Nikitas Papasimakis, Optoelectronics Research Centre & Centre for Photonic Metamaterials, University of Southampton, , United Kingdom
  • Nikolay Zheludev, Optoelectronics Research Centre & Centre for Photonic Metamaterials, University of Southampton, , United Kingdom
We introduce a quantum mechanics inspired approach for the characterization of space-time non-separable waves, such as the Flying Doughnut pulse. We apply techniques analogous to quantum state tomography to quantify the type and degree of non-separability and provide quantitative predictions of the pulse propagation dynamics.
16:15 - 16:30 - D and H Cannot Exist: Topology, Axions, and the Conservation of Global Charge Oral [Show abstract]
  • Jonathan Gratus, Lancaster University and the Cockcroft Institute, United Kingdom
  • Paul Kinsler, Lancaster University and the Cockcroft Institute, United Kingdom
  • Martin McCall, Imperial College, United Kingdom
The excitation fields D&H cannot be directly measured and have gauge freedom. This opens possibilities concerning axionic responses including: (1) a scenario which due to topological reasons is impossible using D&H, (2) allowing periodic lattices with nonzero total charge and (3) an evaporated black hole breaking charge conservation.
16:30 - 17:00 - Boundary Conditions Obtained for Spatially Dispersive Continua from Maxwell's Equations and Constitutive Relations Invited oral [Show abstract]
  • Arthur Yaghjian, Electromagnetics Research, USA
Allowing the polarizations and the fields to have delta functions in the transition layer between free space and spatially dispersive continua, while noting that physically realizable constitutive parameters of spatially dispersive continua must remain finite everywhere, a unique set of a deterministic number of interface boundary conditions can be derived from Maxwell's differential equations.
17:00 - 17:15 - Virtual Critical Coupling for Ideal Energy Storage Oral [Show abstract]
  • Younes Ra'di, Advanced Science Research Center, City University of New York, USA
  • Alex Krasnok , ASRC, CUNY, USA
  • Andrea Alù, Advanced Science Research Center, City University of New York, USA
We extend the notion of critical coupling to high-Q lossless resonators based on tailoring the temporal profile of the excitation wave. Utilizing coupled-mode theory, we demonstrate an effect analogous to critical coupling by mimicking loss with non-monochromatic excitations at complex frequencies. Remarkably, we show that this approach enables unitary excitation efficiency in open systems, even in the limit of extreme quality factors in the regime of quasi-bound states in the continuum.
17:15 - 17:30 - Electromagnetic Responses of Relativistic Quantum Gases and their Natural Left-Handed Behavior Oral [Show abstract]
  • Daniel Medeiros Reis, Centro Brasileiro de Pesquisas Físicas, Brazil
  • Carlos Alberto Aragão de Carvalho, Universidade Federal do Rio de Janeiro, Brazil
We show that relativistic quantum gases behave as left-handed materials at low frequencies by computing their effective responses. Collective plasmon excitations are obtained for both relativistic electron gas (REG) and relativistic Bose gas (RBG). For both, we found a pure photonic mode that propagates with speed of light with no energy dissipated. For such modes, the effective refractive index is n =-1. In addition, the longitudinal dispersion relation for the RBG shows a local minimum gap energy in the condensate phase, analogous to the roton excitation in Helium superfluid
17:30 - 17:45 - Towards Broadband and Compact Giant Nonreciprocity at THz Frequencies Oral [Show abstract]
  • Mohamed Ismail Abdelrahman, Cornell University, USA
  • Francesco Monticone, Cornell University, USA
We unveil a previously overlooked wave propagation regime in magnetized plasmonic materials with comparable plasma and cyclotron frequencies, which enables giant broadband nonreciprocal effects. These findings may pave the way for superior nonreciprocal components, in terms of bandwidth of operation and compactness, in particular at THz frequencies. As a relevant example, we consider Indium Antimonide (InSb) to theoretically demonstrate a subwavelength broadband isolator under moderate magnetic bias at room temperature.
17:45 - 18:00 - Maximal Free-Space Concentration of Electromagnetic Waves Oral [Show abstract]
  • Hyungki Shim, Yale University, USA
  • Haejun Chung, Yale University, USA
  • Owen Miller, Yale University, USA
We derive general bounds to optical superresolution, i.e., maximum intensity for electromagnetic waves from arbitrary wavefront-shaping devices that break the diffraction “limit.” We use inverse design to discover metasurfaces operating close to our bounds.
18:00 - 18:30 - Exponentially-enhanced Quantum Sensing in a Non-Hermitian Lattice without Exceptional Points Invited oral [Show abstract]
  • Aashish Clerk, University of Chicago, USA
We study how unique features of non-Hermitian lattice systems can be harnessed to improve Hamiltonian parameter estimation in a fully quantum setting. While the so-called non-Hermitian skin effect does not provide any distinct advantage, alternate effects yield dramatic enhancements. We show that certain asymmetric non-Hermitian tight-binding models with a Z2 symmetry yield a pronounced sensing advantage: the quantum Fisher information per photon increases exponentially with system size. Such a system can be realized without external gain or loss by using parametric driving (a variant of the recently introduced bosonic Kitaev-Majorana chain). Our setup is directly compatible with a variety of quantum optical and superconducting circuit platforms, and already yields strong enhancements with as few as three lattice sites.
16:00 - Nonreciprocal and topological metamaterials II

Session chairperson(s): Dimitrios Sounas

16:00 - 16:30 - Novel Transport Properties and Isolated States in Topological and Chiral Metasurfaces Invited oral [Show abstract]
  • Dia'aaldin Bisharat, UC San Diego, USA
  • Erda Wen, UC San Diego, USA
  • Sara Kandil, UC San Diego, USA
  • Xiaozhen Yang, UC San Diego, USA
  • Shreya Singh, UC San Diego, USA
  • Robert Davis, UC San Diego, USA
  • Yun Zhou, UC San Diego, USA
  • Prabhakar Bandaru, UC San Diego, USA
  • Daniel Sievenpiper, UC San Diego, USA
This paper will review recent research in photonic topological insulators and chiral metasurfaces, including isolated states and unidirectional propagation, diffusive transport, and applications such as for integrated photonics, scattering control, and antennas, as well as phononic analogs for acoustic applications.
16:30 - 17:00 - Topological Photonics in Three Platforms Invited oral [Show abstract]
  • Mohammad Hafezi, Joint Quantum Institute, USA
We report our recent results on three topological photonics platforms: coupled ring arrays, photonic crystal, and synthetic dimension. In coupled-ring array, we demonstrate how indistinguishable photon pairs can be robustly generated. In the photonic crystal, we show how the topological design principles can be used to create topological resonators with helical edge states, robust against bends. We strongly couple these states to quantum emitters and observe the Purcell effect. Finally, we discuss how synthetic dimensions can be generated in time-delayed fiber loops. We demonstrated how a synthetic magnetic field and an electric field can be created.  
17:00 - 17:15 - Reflection-free Transmission in Reciprocal Slot Line Waveguide Oral [Show abstract]
  • Dia'aaldin Bisharat, University of California San Diego, USA
  • Dan Sievenpiper, University of California San Diego, USA
Interest in realizing reflection-free waveguides recently boomed following discovery of photonic topological insulators, wherein spin-polarized modes are allowed only in opposite directions. Here, we show that guided TEM modes, like in ordinary slot line waveguide, have similar properties, provided that they are properly isolated from all other modes.
17:15 - 17:30 - Continuous Topological Transition from Metal to Dielectric and Hidden Topology Oral [Show abstract]
  • Fan Yang, University of California, San Diego, USA
  • Shaojie Ma, University of Birmingham, UK
  • Kun Ding, Imperial College London, UK
  • Shuang Zhang, University of Birmingham, UK
  • John Pendry, Imperial College London, UK
We propose a new understanding of metal and dielectric by considering them as two limiting cases of a periodic metal-dielectric layered metamaterial. A metal can continuously transform into a dielectric by varying the metal filling ratio form 1 to 0. We further demonstrate a topological invariant in this continuous transition and find an abrupt phase transition when the metal filling ratio is half, which classifying the metamaterials into metallic state and dielectric state. This classification extends our previous understanding of metal and dielectric. Finally, we also study the edge state between metallic state and dielectric state, which offers the surface plasmon polariton (SPP) at a metal/dielectric interface a new physical meaning: the limiting case of a topological edge state.
17:30 - 17:45 - Unidirectional Topological Edge Modes in Optically-Driven Dielectric Lattices Oral [Show abstract]
  • Robert Duggan, University of Texas at Austin, USA
  • Sander Mann, City University of New York, USA
  • Andrea Alù, City University of New York, USA
Previous proposals for one-way topological edge modes have relied mostly on magnetic materials or independently time-modulating a large number of elements independently. We propose a structure that supports these unique edge modes with a uniform driving field over the entirety of the lattice, compatible with dielectric photonic platforms.
17:45 - 18:00 - Crystalline Symmetry Dependent Topological States in Plasmonic Metasurfaces Oral [Show abstract]
  • Matthew Proctor, Imperial College London, United Kingdom
  • Richard V. Craster, Imperial College London, United Kingdom
  • Mehul P. Makwana, Imperial College London , United Kingdom
  • Paloma Arroyo Huidobro, Instituto Superior Técnico, Portugal
A major goal in nanophotonics is to achieve efficient and robust control of light on the subwavelength nanoscale. We utilise the spatial symmetry of a plasmonic metasurface to realise two types of modes: pseudospin dependent modes and topological valley modes. We study the optical response of the systems in the far-field and highlight how it is necessary to include retardation and radiative effects to appropriately model the band structures. Furthermore, we excite edge states locally in the near-field to reveal the nature of the directionality of the modes. From this we show the importance of source position, as well as source polarization, in exciting purely unidirectional modes.
18:00 - 18:30 - Dispersion-Free Floquet Topological Insulator on a Chip Based on Magnetless, Ultra-Compact Quasi-Electrostatic Meta-Molecules Invited oral [Show abstract]
  • Aravind Nagulu, Columbia University, USA
  • Ahmed Kord, Columbia University, USA
  • Xiang Ni, Advanced Science Research Center, City University of New York, USA
  • Andrea Alu, Advanced Science Research Center, City University of New York, USA
  • Harish Krishnaswamy, Columbia University, USA
Artificially-engineered Floquet topological insulators (TIs) based on spatio-temporal modulation of Hermitian potentials has been attracting a lot of attention in recent years thanks to their ability to transport electromagnetic energy in a certain direction without backscattering while at the same time not requiring an external magnetic field as in TIs based on the quantum hall effect (QHE). Prior Floquet TIs were limited to narrow operation bandwidths and remain very challenging to implement in practice due to the difficulty in generating and distributing multi-phased modulation signals across an electrically large lattice with accurate phase synchronization, thus weakening their argument against QHE TIs and prohibiting their use in real applications. In this paper, we address these critical problem by developing a new Floquet TI with a wide topologically protected bandgap from DC up to GHz frequencies by leveraging infinitesimal meta-molecules based on quasi-electrostatic wave propagation in switched capacitor networks. For the first time, we present the implementation of a floquet TI on a chip, thus opening the door to numerous applications of TIs in wireless communications and integrated photonics.
16:00 - Plasmonics II

Session chairperson(s): Xuefeng Jiang

16:00 - 16:30 - High Efficiency THz-to-RF Wavelength Conversion Through Plasmonic Photoconductive Nanostructures Invited oral [Show abstract]
  • Mona Jarrahi, UCLA, USA
Detection of faint fluxes of photons at terahertz frequencies is crucial for various applications including biosensing, medical diagnosis, chemical detection, atmospheric studies, space explorations, high-data-rate communication, and security screening. Heterodyne terahertz spectrometers based on cryogenically cooled superconducting mixers have so far been the only instruments that can provide high spectral resolution and near-quantum-limited sensitivity levels. The operation temperature, bandwidth constraints, and complexity of these terahertz spectrometers have restricted their use to mostly astronomy and atmospheric studies, limiting the overall impact and wide-spread use of terahertz technologies. Here we introduce a spectrometry scheme that uses plasmonic photomixing for terahertz-to-radio frequency downconversion to offer quantum-level sensitivities at room temperature for the first time. Frequency downconversion is achieved by mixing terahertz radiation and a heterodyning optical beam with a terahertz beat frequency in a plasmonics-enhanced semiconductor active region. We demonstrate spectrometer sensitivities down to 3 times the quantum-limit at room temperature. Our presented spectrometry scheme can be applicable to resolve both the high-resolution spectra of gas molecules and mid-resolution spectra of condensed phase samples over a total operable bandwidth of 0.1-5 THz. As an example, we use the presented spectrometer to resolve the spectral information of ammonia, which has a number of narrowband absorption peaks over the 0.1-5 THz frequency range. With a versatile design capable of broadband spectrometry, this plasmonic photomixer has broad applicability to quantum optics, chemical sensing, biological studies, medical diagnosis, high data-rate communication, as well as astronomy and atmospheric studies.
16:30 - 16:45 - Demonstration and Tuning of Tamm Plasmons at the Interface with Metasurfaces Oral [Show abstract]
  • Vassili Fedotov, University of Southampton, UK
  • Oleksandr Buchnev, University of Southampton, UK
  • Alexandr Belosludtsev, Center for Physical Sciences and Technology, Lithuania
  • Victor Reshetnyak, Taras Shevchenko National University of Kyiv, Ukraine
  • Dean Evans, Air Force Research Laboratory, USA
We demonstrate experimentally that Tamm plasmons can be supported by a dielectric mirror interfaced with a metasurface, a discontinuous thin metal film periodically patterned on the sub-wavelength scale. Not only do Tamm plasmons survive the nano-patterning of the metal film, but they also become sensitive to external perturbations, as a result. In particular, by depositing a nematic liquid crystal on the outer side of the metasurface we were able to red-shift a Tamm plasmon by 35 nm, while electrical switching of the liquid crystal enabled us to tune the wavelength of this notoriously inert excitation within 10 nm.
16:45 - 17:00 - Thermal Manipulation of Plasmons in Atomically Thin Films Oral [Show abstract]
  • Eduardo Brioso Dias, ICFO - The Institute of Photonic Sciences, Spain
  • Renwen Yu, ICFO - The Institute of Photonic Sciences, Spain
  • F. Javier García de Abajo, ICFO - The Institute of Photonic Sciences, Spain
Nanoscale photothermal effects enable important applications in cancer therapy, imaging and catalysis. These effects also induce substantial changes in the optical response experienced by the probing light, thus suggesting their application in all-optical modulation. Here, we demonstrate the ability of graphene, thin metal films, and graphene/metal hybrid systems to undergo photothermal optical modulation with depths as large as >70% over a wide spectral range extending from the visible to the terahertz frequency domains.
17:00 - 17:30 - Quantum Theory of Radiative Decay Rate and Frequency Shift of Surface Plasmon Modes in Interacting Arbitrarily Shaped Nanoparticles Extended oral [Show abstract]
  • Carlo Forestiere, University of Naples, Italy
  • Giovanni Miano, University of Naples, Italy
  • Mariano Pascale, University of Naples, Italy
  • Roberto Tricarico, ICFO Institut de Cie`ncies Foto`niques, Spain
We derive non-perturbative closed form expressions of decay rate and frequency shift of plasmon modes in terms of their quasistatic spatial distribution, by studying the dynamics of the expectation values of the plasmon creation and annihilation operators.
17:30 - 17:45 - Harmonising Nonlocal and Local Formalism for Overlapping Plasmonics Nanowires Oral [Show abstract]
  • Ruben Alves, University of Birmingham, United Kingdom
  • Ariel Guerreiro, University of Porto, Portugal
  • Miguel Navarro-Cia, University of Birmingham, United Kingdom
The nonlocal dynamics of the electrons in a plasmonic structure are commonly described using the hydrodynamic Drude model (HDM) based on the fluid equations. Here, we re-write the fluid equations with the Madelung formalism as a nonlinear Schr¨odinger equation to provide a more natural bridge between quantum mechanics and plasmonics. We then apply this formalism to a system composed of two overlapping nanowires and compare it with classical electrodynamics to ensure that the local approximation holds, identifying in the process the corrections needed.
16:00 - Optical metamaterials I

Session chairperson(s): Seunghwi Kim

16:00 - 16:30 - Metamaterial Based Spectro-polarimetric Systems Invited oral [Show abstract]
  • Giampiero Gerini, TNO - Optics Department; Technology University of Eindhoven, Netherlands
  • Pjotr Stoevelaar, TNO - Optics Department; Technology University of Eindhoven, Netherlands
  • Tiberiu Ceccotti, TNO - Optics Departmen, Netherlands
In this work, we present three different metamaterial based spectro-polarimetric systems. Their principles of operation and their performances are briefly discussed. A more detailed analysis of the three systems and the results of the experimental characterization of the first concept will be presented at the conference.
16:30 - 16:45 - Optimal Monitoring of Small Polarization Perturbations with Metasurfaces Oral [Show abstract]
  • Shaun Lung, The Australian National University, Australia
  • Jihua Zhang, The Australian National University, Australia
  • Kai Wang, The Australian National University, Australia
  • Khosro Zangeneh Kamali, The Australian National University, Australia
  • Mohsen Rahmani, The Australian National University, Australia
  • Dragomir Neshev, The Australian National University, Australia
  • Andrey Sukhorukov, The Australian National University, Australia
We reveal that dielectric metasurfaces can perform tailored non-conservative transformations optimized for monitoring of small deviations around arbitrarily chosen linear, circular, or elliptical polarizations. We demonstrate that such metasurfaces can convert the anchor polarization to horizontal linear polarization with attenuated power, while they map the small deviations to vertical linear polarization with nearly full power, delivering amplified vertical-to-horizontal polarization ratios for sensitive and convenient single-shot detection.
16:45 - 17:00 - Deep Learning for Generalized Multiobjective Optimization of Metamaterials Oral [Show abstract]
  • Ronald Jenkins, Penn State University, USA
  • Philip O'Connor, Penn State University, USA
  • Sawyer Campbell, Penn State University, USA
  • Pingjuan Werner, Penn State University, USA
  • Douglas Werner, Penn State University, USA
The inverse-design of metamaterials often requires full-wave evaluation of an enormous number of different candidate designs, which can be extremely time consuming and, in many cases of practical interest, even intractable. By introducing deep learning at an early stage in the design process, a generalized network can be paired with multiobjective optimization to rapidly solve a variety of complex electromagnetic metamaterial design problems.
17:00 - 17:15 - High-Uniformity, High-Performance Double Material Dielectric Diffractive Metagratings Oral [Show abstract]
  • Oksana Shramkova, Interdigital, France
  • Valter Drazic, Interdigital, France
  • Laurent Blondé, Interdigital, France
  • Bobin Varghese, Interdigital, France
  • Valerie Allié, Interdigital, France
In this work we propose a solution for the creation of a nanojet focusing component based on a combination of two dielectric materials capable of managing the position of the focused beam in the near zone. We demonstrate that the double-material design of the elements of metagratings can be used to change its diffraction properties improving the diffraction efficiency and diffraction uniformity
17:15 - 17:30 - Design Methods for 3D Membrane Projection Lithography Metasurface Unit Cells Oral [Show abstract]
  • Eric B. Whiting, The Pennsylvania State University, USA
  • Sawyer D. Campbell, The Pennsylvania State University, USA
  • Douglas H. Werner, The Pennsylvania State University, USA
  • Pingjuan L. Werner, The Pennsylvania State University, USA
Three dimensional metasurface structures hold the potential for better performing devices and interesting new properties. However, at optical frequencies it is very difficult to fabricate truly three dimensional designs. One of the most promising techniques is Membrane Projection Lithography (MPL), which can allow for dielectric and metallic inclusions to be deposited on the side wall of a cavity. However, the design process is difficult due to the large search space afforded by these 3D structures and the many coupling environments that arise between neighboring unit cells. Fortunately, advanced optimization techniques have been developed that allow for the space to be fully explored in an efficient manner for optimal designs.
17:30 - 17:45 - Tunable Fano Resonance in a Liquid Crystal Colloidal Metamaterial Oral [Show abstract]
  • Amit Bhardwaj, Centre for Nano and Soft Matter Sciences, Bengaluru, India
  • Dr. Vimala Sridurai, Centre for Nano and Soft Matter Sciences, Bengaluru, India
  • Dr. Navas M P , Centre for Nano and Soft Matter Sciences, Bengaluru, India
  • Aswathi Nair, Centre for Nano and Soft Matter Sciences, Bengaluru, India
  • Tripti Ahuja, Indian Institute of Technology, Madras, India
  • Dr. Geetha Nair, Centre for Nano and Soft Matter Sciences, Bengaluru, India
A colloidal metamaterial is realized by dispersing submicron-sized high-refractive-index dielectric resonators in a nematic liquid crystal medium. Darkfield hyperspectral imaging reveals that when the NLC molecules reorient on application of an ac electric field a doughnut-shaped scattering pattern is obtained, indicating the occurrence of Fano resonance. The theoretical simulation based on the ‘Multi-pole Fano interference model’ confirms the experimental findings. With increasing voltage, the value of Fano parameter q decreases and approaches unity corresponding to an ideal Fano shape.
17:45 - 18:00 - Can we Bring EM Enhancement to the Multi-wavelength Scale? Oral [Show abstract]
  • Stavroula Foteinopoulou, U. of New Mexico, USA
EM enhancement is typically a lensing-type of effect by which a wide input beam couples to spatially localized resonant modes as for example Mie plasmons, void plasmons or Mie modes at high refractive index particles. Accordingly, EM enhancement is inherently a sub-wavelength phenomenon. Here, we explore a different paradigm for EM enhancement that is based on EM energy being collected over large time intervals by means of an ultra-slow-light waveguide.
18:00 - 18:30 - Machine-Learning-Assisted Photonics Invited oral [Show abstract]
  • Zhaxylyk A. Kudyshev, ,
  • Alexander V. Kildishev, ,
  • Vladimir M. Shalaev, Purdue University, USA
  • Alexandra Boltasseva, Purdue University, USA
We coupled adversarial autoencoder deep generative network with adjoined topology optimization technique to advance metasurface design. The proposed approach speeds up the optimization search of highly efficient metasurface designs and also provides unparalleled control over the compressed design space distribution. The latter fact assures scalability of the approach to highly-constrained optimization problems. With the recent progress in emerging photonic material platforms, as well as advances in fabrication techniques, nanophotonics can provide solutions to interdisciplinary challenges in energy [1], quantum IT [2] and other areas. Addressing multifaceted problems require highly-constrained optimization of the device design, due to inherent complexity and multi-disciplinary nature of any practical application. Conventionally, adjoint [3] and genetic [4] optimization methods have been used to address such optimization tasks. However, the computational power requirement of these methods scales up with the number of constraints. This fact substantially limits the applicability of conventional optimization techniques to real-life applications. Within this work, we merged the adjoint topology optimization technique with adversarial autoencoders (AAE) to achieve significant improvement in the optimization search of non-trivial nano-antenna-based metasurface designs [5]. Particularly, we demonstrated that the proposed approach ensures not only the efficient optimization search of high-performance metasurface designs but also provides unparalleled control over the compressed design space distribution. The latter fact assures scalability of the approach to highly-constrained optimization problems. To showcase AAE-assisted method, we optimized a metasurface thermal emitter for thermophotovoltaic (TPV) applications. Compared to an adjoint-based topology optimized design with 92% efficiency of the thermal emission reshaping, the proposed method provides three times speed-up and gives 98% efficiency. The proposed approach can be adapted to a broader scope of the problems in optics, chemistry, and mechanics.
29 September 2020 / Start time: 9 h 0 min
09:00 - 10:00 - Plenary Session II
09:00 - Plenary Session II

Session chairperson(s): Stefano Maci

09:00 - 10:00 - Metamaterials, Artificial Intelligence and Deeply Subwavelength Optical Imaging and Metrology Plenary [Show abstract]
  • Nikolay Zheludev, University of Southampton, UK and NTU, Singapore, United Kingdom and Singapore
<p> A number of ideas have been explored by the metamaterials community on how to achieve far-field optical super-resolution in imaging. A practical solution is closer than we anticipated. We demonstrate metrology and optical imaging with deeply subwavelength resolution in different modalities based on the use of artificial intelligence and light topologically structured by metasurfaces.</p>
10:00 - 10:30 - Coffee Break (Tuesday Morning)
10:30 - 12:30 - Oral Sessions (Tuesday Morning)
10:30 - Special session: Epsilon-near-zero media: theory and applications

Organizer(s): Humeyra Caglayan; Iñigo Liberal

Session chairperson(s): Sander Mann

10:30 - 11:00 - ENZ Optics Invited oral [Show abstract]
  • Nader Engheta, University of Pennsylvania, USA
I give an overview of the field of epsilon-near-zero (ENZ) optics. I discuss some of the salient features of wave interaction in this platform, and present some of its potential applications.
11:00 - 11:15 - Temporal and Spatial Manipulations of Optical Waves with Time-varying Nonlinear Epsilon-Near-Zero Metastructures Oral [Show abstract]
  • M. Zahirul Alam, University of Ottawa, Canada
  • Robert Boyd, University of Ottawa and University of Rochester, Canada
We experimentally demonstrate that the large optical nonlinearity of epsilon-near-zero materials can be used to manipulate light beams in time and in space domains. We specifically discuss wavelength conversion due to time refraction and real-time image processing with THz refresh rate using a subwavelength-thick epsilon-near-zero thin film.
11:15 - 11:30 - The Role of Absorption and Non-Parabolicity in Nonlinear Epsilon-Near-Zero Materials Oral [Show abstract]
  • Ray Secondo, Virginia Commonwealth University, USA
  • Jacob B. Khurgin, Johns Hopkins University, USA
  • Nathaniel Kinsey, Virginia Commonwealth University, USA
We look at the underlying cause of the intensity-dependent refractive index in heavily doped epsilon-near-zero semiconductors and highlight the effects of absorption and band non-parabolicity in the model. A figure of merit is proposed to evaluate new candidate materials for nonlinear applications.
11:30 - 11:45 - Epsilon Near Zero Phenomena: From Enhanced Light Matter Interaction to Ultrafast Switching and High Harmonic Generation Oral [Show abstract]
  • Igal Brener, Sandia National Labs, USA
Epsilon Near Zero (ENZ) materials exhibit many different fascinating phenomena. In this talk I will survey some of the fundamentals of ENZ modes and experimental results in light-matter interaction and nonlinear optical phenomena using semiconductors as ENZ materials.
11:45 - 12:00 - Multiple Metal/Insulator/Metal Cavities as a Platform to Design Epsilon-Near-Zero Resonances Oral [Show abstract]
  • Roman Krahne, Optoelectronics, Istituto Italiano di Tecnologia, Italy
  • Lyuye Lin, IIT, Italy
  • Renuka Devi Pothuraju, IIT, Italy
  • Giulia Biffi, IIT, Italy
  • Remo Proietti Zaccaria, IIT, Italy
  • Antonio De Luca, Università della Calabria, Italy
  • Vincenzo Caligiuri, Università della Calabria, Italy
Layered Metal/Insulator/Metal cavities sustain Epsilon-Near-Zero (ENZ) resonances that can be tuned across the visible range. We discuss the effects of lateral patterning of such cavities, and the properties of multilayer stacks. The latter show ENZ bands formed by mode coupling that can be described with the Kronig-Penney model.
12:00 - 12:15 - Optically Tunable Epsilon-Near-Zero Metamaterials Oral [Show abstract]
  • Humeyra Caglayan, Tampere University, Finland
In this study, we obtained epsilon-near-zero metamaterial at visible range by designing and fabricating a metal–dielectric multilayer anisotropic hyperbolic metamaterial. To do this, we experimentally characterize and extract the permittivity from the TMM (transfer matrix method). Later, we show by optically pumping with fs pulses at a proper wavelength the ENZ point of the structure alters, in comparison to the linear case. The change in the effective permittivity happens in the order of unity, leading to ultrafast light induced refractive index change.
12:15 - 12:30 - Material-Based High-Impedance Surfaces for Thermal Engineering Applications Oral [Show abstract]
  • Iñigo Liberal, Universidad Publica de Navarra, Spain
  • José Manuel Péres-Escudero, Universidad Publica de Navarra, Spain
High-impedance surfaces are metamaterial constructs that enable the design of low-profile antennas, electromagnetic absorbers, beamforming and anti-radar systems. In our talk, we will discuss how continuous epsilon-near-zero (ENZ) media enables high-impedance surfaces that do not require from nanofabrication, do not suffer from spatial dispersion, their geometry is not limited by the size of the unit-cell, and are able to recover subwavelength near-field details. As an example, here we theoretically and experimentally demonstrate how a silicon carbide substrate enhances the absorption on a titanium thin film.
10:30 - Active and non-linear I (New Journal of Physics session)

Session chairperson(s): Nikolina Jankovic

10:30 - 11:00 - Spintronic-Plasmonic Metasurfaces for Broad-Band Infrared Response Modulation with Magnetic Fields Invited oral [Show abstract]
  • Javier Aizpurua, Center for Materials Physics (CSIC-UPV/EHU), Spain
  • Luca Bergamini, Department of Electronics and Electricity, FCT-ZTF, UPV/EHU, Spain
  • Nerea Zabala, Department of Electronics and Electricity, FCT-ZTF, UPV/EHU, Spain
  • Gaspar Armelles, Instituto de Micro y Nanotecnología, IMN-CNM, CSIC (CEI UAM+CSIC),Madrid, Spain
  • María Ujué-Gozález, Instituto de Micro y Nanotecnología, IMN-CNM, CSIC (CEI UAM+CSIC),Madrid, Spain
  • Fernando García, Instituto de Micro y Nanotecnología, IMN-CNM, CSIC (CEI UAM+CSIC),Madrid, Spain
  • Raquel Alvaro, Instituto de Micro y Nanotecnología, IMN-CNM, CSIC (CEI UAM+CSIC),Madrid, Madrid
  • Alfonso Cebollada, Instituto de Micro y Nanotecnología, IMN-CNM, CSIC (CEI UAM+CSIC),Madrid, Spain
We experimentally demonstrate and theoretically confirm that metasurfaces consisting of arrays of randomly distributed spintronic-plasmonic antennas (slits or rods) fabricated with Ni81Fe19/Au multilayers exhibit Giant Magneto Resistance (GMR) and show spintronic modulation of their optical and mid-infrared response, using very weak magnetic fields.
Media link(s):

We experimentally demonstrate and theoretically confirm that metasurfaces consisting of arrays of randomly distributed plasmonic antennas (slits or rods) fabricated with Ni81Fe19/Au multilayers exhibit GMR and show spintronic modulation of their optical and mid infrared response, using very weak magnetic fields

11:00 - 11:15 - Synthesis of NIC-based Reflection Amplifiers for Metasurfaces Oral [Show abstract]
  • Josip Lončar, University of Zagreb, Croatia
  • Anthony Grbic, University of Michigan, United States
  • Zvonimir Šipuš, University of Zagreb, Croatia
Reflection amplifiers can be used to amplify an incident electromagnetic wave impinging onto a metasurface upon reflection without compromising stability. Here, a reflection amplifier based on a negative-impedance converter is proposed and its stability properties examined. The stability highly depends on the loading impedance and can be achieved by using a shunt resonator, which limits the bandwidth of the amplifier to fit the bandwidth of the load.
11:15 - 11:30 - Overcoming Mantle Cloaking Limits In Antenna Applications Through Non-Linear Metasurfaces Oral [Show abstract]
  • Stefano Vellucci, ROMA TRE University, Italy
  • Alessio Monti, Niccolò Cusano University, Italy
  • Mirko Barbuto, Niccolò Cusano University, Italy
  • Marco Salucci, ELEDIA Research Center , Italy
  • Giacomo Oliveri, ELEDIA Research Center , Italy
  • Alessandro Toscano, ROMA TRE University, Italy
  • Filiberto Bilotti, ROMA TRE University, Italy
In this contribution, the fundamental bounds that apply to low-scattering antennas are discussed and the use of non-linear cloaking metasurfaces is proposed to overcome them. Different power-dependent mantle cloak designs, which are able to dynamically transforming their effective geometry depending on the power level of the impinging field, are introduced. Their effectiveness is assessed in several antenna and array scenarios. This innovative approach may find applications in all those radiating systems in which a considerable difference between transmitted and received power levels is present.
11:30 - 11:45 - Efficient Implementation of Active Exterior Cloaking in Three Dimensions Oral [Show abstract]
  • Cheuk-Him Yeung, University of Manchester, United Kingdom
  • Tom Shearer, University of Manchester, United Kingdom
  • William J. Parnell, University of Manchester, United Kingdom
We describe a cloaking strategy for the 3D Helmholtz equation that uses multipolar sources located at the vertices of an imaginary Platonic solid to construct a silent region which shields any object inside from an incoming wave. The source amplitudes can be conveniently determined using the symmetry of the configuration.
11:45 - 12:00 - A Phase Conjugating Metasurface Oral [Show abstract]
  • Francis Salas, University of Michigan, USA
  • Anthony Grbic, University of MIchigan, USA
  • Waleed Alomar, KACST, Saudi
This paper presents the design of a phase conjugating metasurface operating at 10 GHz. The designed metasurface achieves phase conjugation, by heterodyning (mixing) an incident RF signal with a pump (modulation) signal at twice the frequency of the incident RF signal. Frequency mixing is achieved through the use of fast switching Schottky diodes. The unit cell of the metasurface is composed of a subwavelength metallic patch that is aperture coupled to the heterodyning circuit. Metasurfaces offer a low-profile alternative to retrodirective antenna arrays. Such metasurfaces could play a key role in far-field wireless power transfer systems.
12:00 - 12:30 - Near-Zero Power Integrated Microsystems for the IoT Invited oral [Show abstract]
  • Matteo Rinaldi, Northeastern University, USA
As a consequence of the internet-of-things revolution, the number of connected devices worldwide is expected to increase to 50–200 billion by 2020. To maintain such a large network, there is a need for wireless sensors with dimensions and power consumption that are orders of magnitude smaller than the state-of-the-art. Energy is the key challenge. Batteries have limited capacity, and existing sensors are not “smart” enough to identify targets of interest. Therefore, they consume power continuously to monitor the environment even when there is no relevant data to be detected. This talk presents a new class of zero-power microsystems that fundamentally brake this paradigm, remaining dormant, with zero-power consumption, until awakened by a specific physical signature associated with an event of interest. In particular, we demonstrate infrared digitizing sensors that consist of plasmonically enhanced micromechanical photoswitches (PMPs) that selectively harvest the impinging electromagnetic energy in design-defined spectral bands of interest and use it to create mechanically a conducting channel between two electrical contacts, without the need for any additional power source. Such a passive IR digitizer is capable of producing a wake-up bit when exposed to a specific IR spectral signature associated to a target of interest (such as the exhaust plume of a car, a forest fire, or a human body) while rejecting background interference. The capability of these zero-power sensors of consuming power only when useful information is present results in a nearly unlimited duration of operation, with a groundbreaking impact on the proliferation of the IoT.
10:30 - Special session: Theory of Photonic Waves in Novel Materials

Organizer(s): Amir Sagiv; Michael Weinstein

Session chairperson(s): Angelica Viola Marini

10:30 - 11:00 - Light Confinement in Coreless Twisted Photonic Crystal Fibers Invited oral [Show abstract]
  • Austin Copeland, Southern Methodist University, USA
  • Alejandro Aceves, Southern Methodist University, USA
Recent work have shown light confinement can occur during propagation through a twisted coreless photonic crystal fiber (a chiral fiber). In the absence of a twist, the modal profile is assumed known from Bloch theory and assumed not to be confined. By use of asymptotic techniques applied to the field propagation equation, we provide a theoretical framework in support of observed confinement. While we do this for a particular periodic index profile, recent experiments suggest this to be a robust effect. In this work, we also explore the problem both in the linear and the nonlinear regime. We show that an increase in twist rate will result in more confined modes and indications that nonlinearity plays a secondary role on confinement.
11:00 - 11:15 - Atomic Waveguides: One-dimensional Quantum Metamaterials Oral [Show abstract]
  • Ana Asenjo-Garcia, Columbia University, USA
Atom arrays are an exciting new type of quantum light-matter interface. One-dimensional ordered arrays can be used as atomic waveguides. Their guided modes mediate tunable, long-range interactions between impurity atoms coupled to the chain. The waveguides are intrinsically quantum and display strong nonlinearities, allowing for the exploration of many-body physics between photons and the realization of single-photon switches and transistors.
11:15 - 11:30 - Nonlinear Topological Photonics Oral [Show abstract]
  • Bo Zhen, University of Pennsylvania, USA
Achieving topologically protected robust transport in optical systems has recently been of great interest. Most studied topological photonic structures can be understood by solving the eigenvalue problem of Maxwell’s equations for static linear systems. Here, we extend topological phases into dynamically driven nonlinear photonic systems. Floquet topological phases in both 1D and 2D will be discussed.
11:30 - 11:45 - TE Band Structure For High Contrast Honeycomb Media Oral [Show abstract]
  • Maxence Cassier, Institut Fresnel (CNRS), France
  • Michael Weinstein, Columbia University, Dept. of Applied Physics and Applied Mathematics, and Dept. of Mathematics, United States
We study the band structure of transverse electric waves in 2D high contrast honeycomb media. Using analytical ideas, together with numerical simulations, we obtain detailed local information, such as the existence of Dirac points, as well as global behavior of the dispersion surfaces over the full Brillouin zone.
11:45 - 12:00 - Bulk Soliton Dynamics in Bosonic Topological Insulators Oral [Show abstract]
  • Jeremy Marzuola, University of North Carolina, USA
We theoretically explore the dynamics of spatial solitons in nonlinear/interacting bosonic topological insulators. We employ a time-reversal broken Lieb-lattice analog of a Chern insulator and find that in the presence of a saturable nonlinearity, solitons bifurcate from a band of non-zero Chern number into the topological band gap with vortex-like structure on a sub-lattice. I will also discuss some further explorations of nonlinear bifurcations in other topological models and properties of continuum mathematical models if time allows.
12:00 - 12:15 - Optical Phenomena and Resonances in the Homogenization of Layered Heterostructures Oral [Show abstract]
  • Matthias Maier, Texas A&M University, USA
We present an adaptive, higher-order finite element approach for the simulation of optical phenomena on layered heterostructures: We present a homogenization theory of such plasmonic crystals and introduce a heterogeneous multiscale method based on the analytic homogenization result. We conclude with a spectral analysis quantitatively describing Lorentz resonances in the effective permittivity tensor.
12:15 - 12:30 - Losses of Slow Interface Waves in Plasmonic and Spintronic Structures Oral [Show abstract]
  • Alex Schuchinsky, University of Liverpool, United Kingdom
The loss mechanisms of slow waves guided by media interfaces are discussed by examples of surface plasmon polaritons and spin waves. It is shown that plasmons and spin waves with propagation constants kn have anomalously high losses ~kn3, which are directly related to vortices of the wave power flow.
12:30 - 13:00 - Control of Light at the Atomic Scale: Fundamentals and Applications Invited oral [Show abstract]
  • Javier García de Abajo, ICFO - Institut de Ciencies Fotoniques, Spain
We will discuss recent advances in the study of fundamental aspects and applications of plasmons and other types of polaritons in two-dimensional systems including atomically thin metal films.
10:30 - Time-space modulating metamaterials

Session chairperson(s): Robert Duggan

10:30 - 11:00 - Spacetime Metamaterial Perspective Invited oral [Show abstract]
  • Christophe Caloz, KU Leuven, Belgium
The paper presents the perspective of the author on the novel paradigm of spacetime metamaterials. It presents this emergent field as an extension of relativity physics and modulated-device engineering, and discusses the unprecedented opportunities that such metamaterials offer in terms of the simultaneous control of the spatial and temporal spectra of waves.
11:00 - 11:30 - Theory of Wave Propagation in Luminal Space-Time Crystals: a new Mechanism for Amplification Invited oral [Show abstract]
  • John Pendry, Imperial College London, United Kingdom
  • Emanuele Galiffi, Imperial College London, UK
  • Paloma Huidobro, 2Instituto de Telecomunicações, Insituto Superior Técnico-University of Lisbon, Portugal
In this talk we identify a new mechanism for pulse amplification: the compression of lines of force that are nevertheless conserved in number. Time dependent systems do not in general conserve energy invalidating much of the theory developed for static systems and turning our intuition on its head. This is particularly acute in luminal space time crystals where the structure moves at or close to the velocity of light. Conventional Bloch wave theory no longer applies, energy grows exponentially with time, and a new perspective is required to understand the phenomenology. Analytic approximations are also presented.
11:30 - 12:00 - From Polarizability to Effective Permittivity of Time-Varying Materials Invited oral [Show abstract]
  • S.M. Mirmoosa, Swiss Federal Institute of Technology in Lausanne (EPFL), Switzerland
  • T.T. Koutserimpas, Swiss Federal Institute of Technology in Lausanne (EPFL), Switzerland
  • G.A. Ptitcyn, Aalto University, Finland
  • S.A. Tretyakov, Aalto University, Finland
  • R. Fleury, Swiss Federal Institute of Technology in Lausanne (EPFL), Switzerland
<p> In this talk, we describe excitation of time-varying dipolar particles (time-modulated meta-atoms) by external time-varying fields from a nonstationary and causal perspective. For a time-harmonic excitation, we introduce a complex-valued function, called temporal complex polarizability, and use this function to study a classical electron through the equation of motion whose damping coefficient and natural frequency are changing in time. We theoretically derive the temporal complex permittivity corresponding to time-varying media formed by time-modulated meta-atoms and explicitly show the differences with the conventional macroscopic Drude-Lorentz model.</p>
12:00 - 12:15 - Magnet-Free Circulator Formed by a Time-Varying Nonreciprocal Phase Shifter Oral [Show abstract]
  • Sajjad Taravati, University of Toronto, Canada
  • George V. Eleftheriades, University of Toronto, Canada
We propose a highly efficient magnet-free ring circulator constituted of a nonreciprocal time-varying phase shifter. Such a circulator introduces strong nonreciprocity between its isolated ports and possesses a simple architecture.
10:30 - Near-field imaging

Session chairperson(s): Alex Krasnok

10:30 - 11:00 - Probing Optical Near-fields with High-energy Electrons: Holography, Topological crystals, and Quantum Correlations Invited oral [Show abstract]
  • Albert Polman, AMOLF, Netherlands
We use 5-30 keV cathodoluminescence spectroscopy to measure plasmonic scattering wavefronts using holography, determine the density of states and band structure of topological Si photonic crystals, unravel the near-field state transfer of diamond NV centers, and probe optical near fields that control quantum electron wavepackets in space and time.
11:00 - 11:30 - Metasurfaces and Fourier Imaging for Sensing and Metrology Invited oral [Show abstract]
  • Femius Koenderink, Center for Nanophotonics, AMOLF, Netherlands
  • Robin Buijs, Center for Nanophotonics, AMOLF, Netherlands
  • Ruslan Rohrich, Center for Nanophotonics, AMOLF, Netherlands
  • Tom Wolterink, Center for Nanophotonics, AMOLF, Netherlands
  • Nick Schilder, Center for Nanophotonics, AMOLF, Netherlands
  • Ewold Verhagen, Center for Nanophotonics, AMOLF, Netherlands
Metasurface motifs and plasmonic oligomers can have diffraction patterns rich in features in intensity, polarization and phase, leveraging strong multiple scattering, near-field hybridization of resonances, and the coupling of photon spin, angular momentum, and multipoles. Here we demonstrate the utility of these diffraction patterns for metrology, asking how to optimally encode and extract near-field information in far field radiation patterns.
11:30 - 11:45 - Quantum Effects in the Interaction of Optical Excitations and Fast Electrons Oral [Show abstract]
  • Valerio Di Giulio, ICFO, Institut de Ciencies Fotoniques, Spain
  • Mathieu Kociak, Laboratoire de Physique des Solides, CNRS, Université Paris Sud XI, F 91405 Orsay, France, France
  • Javier García de Abajo, ICFO, Institut de Ciencies Fotoniques, Spain
We investigate the interaction between fast electrons and confined optical excitations which are allowed to experience quantum fluctuations. In particular, we explore the effects that the quantum nature of light induces on the electron wave function and the possibility of retrieving its second-order correlation function through the intensities of the peaks in the electron energy spectrum.
11:45 - 12:00 - High-refractive-index Nanosparticles on Optical Fibres for High-Resolution Lensing Applications Oral [Show abstract]
  • Wasem Aljuaid, School of Mathematics Statistics and Physics, Newcastle University, United Kingdom
  • Noel Healy, School of Mathematics Statistics and Physics, Newcastle University, United Kingdom
  • Victor Pacheco-Peña, School of Mathematics Statistics and Physics, Newcastle University, United Kingdom
We propose a mechanism to produce high-resolution spatial focusing at telecommunication wavelengths by using high-refractive index nanoparticles. We are able to generate photonic nanojets by carefully engineering truncated nanospheres placed on an optical fibre achieving a focal spot with high transverse resolution of less than 0.25λ.
12:00 - 12:15 - The Influence of Strong Coupling on Photobleaching Suppression Oral [Show abstract]
  • Nikita Nefedkin, City University of New York, Advanced Science Research Center, Photonics Initiative , USA
  • Evgeny Andrianov, Dukhov Research Institute of Automatics, Russia
  • Alexey Vinogradov, Institute for Theoretical and Applied Electromagnetics, Russia
The significant suppression of photobleaching can be observed in a system of a J-aggregated organic choromophore and a plasmonic nanostructure in strong coupling regime. In the present work, we show that this suppression is connected with the temperature of the environment, namely, the ratio of the interaction energy between the near field of the plasmonic nanostructure and the dipole moment of J-aggregated molecule and the energy of thermal fluctuations in the molecule. We also demonstrate the existence of an optimal value of red detuning between the plasmon resonance frequency and the frequency of exciton in J-aggregate for which the photobleaching suppression is the largest. These results reveal the role of strong coupling between a plasmonic nanostructure near field and a molecular dipole moment in the photobleaching suppression.
12:15 - 12:30 - On the Radiative Emission and Excitation Rate of Quantum Emitters in Plasmonic Nanostructures Oral [Show abstract]
  • Kalun Bedingfield, University of Birmingham, United Kingdom
  • Angela Demetriadou, University of Birmingham, United Kingdom
Using a multipolar decomposition of a system’s plasmonic modes, we show that in plasmonic structures beyond the quasi-static limit, an emitter radiates energy much more efficiently than a plane wave couples energy into the antenna. These results significantly impact our understanding and interpretation of the light-matter dynamics.
12:30 - 14:00 - Lunch Break (Tuesday)
14:00 - 15:30 - Oral Sessions (Tuesday Afternoon 1)
14:00 - Metamaterials for nanoelectronics and nanophotonics

Session chairperson(s): Sander Mann

14:00 - 14:30 - Tailoring the Interactions Between Electric and Magnetic Dipoles in Plasmonic and Dielectric Metasurfaces Invited oral [Show abstract]
  • Alessio Monti, Niccolò Cusano University, Italy
  • Andrea Alù, CUNY Advanced Science Research Center, USA
  • Alessandro Toscano, ROMA TRE University, Italy
  • Filiberto Bilotti, ROMA TRE University, Italy
In this contribution, we review some of our recent efforts in the investigation of unusual properties of plasmonic and dielectric metasurfaces. We first outline the fundamentals of a surface impedance homogenization approach, which has resulted to be suitable for effectively describing the macroscopic response of metasurfaces made by spheroidal atoms for both normal and oblique incidences. Then, we will describe some of our findings about the unconventional applications of these structures at microwave and optical frequencies.
14:30 - 15:00 - Inverse Design of Nanophotonic Devices with Structural Integrity Extended oral [Show abstract]
  • Yannick Augenstein, KIT, Germany
  • Carsten Rockstuhl, KIT, Germany
With recent developments in additive manufacturing techniques, a vast design space of free-form photonic devices is opening up. To make use of this, we present a new approach to inverse design in nanophotonics by fusing it with structural topology optimization.
15:00 - 15:15 - Simultaneous Stretching and Unwinding of Helical Elements of Metamaterials under the Influence of an Electromagnetic Wave Oral [Show abstract]
  • Ivan Mikhalka, Francisk Skorina Gomel State University, Belarus
  • Igor Semchenko, Francisk Skorina Gomel State University, Belarus
A smooth helix, widely used as an element of metamaterials and metasurfaces, is studied in an external field under half-wave resonance conditions. The axial and tangential components of the electric force acting on the charges in the helix from the side of the incident wave have been calculated. It is shown that the moment of force, having an axial direction, arises simultaneously with the force directed along the axis of the helix. The action of these factors can lead to the simultaneous stretching and unwinding of the helix in the field of the external wave. The results can be used when considering equilibrium and retention the helix shape, including as an element of metamaterials. The possibilities of tailoring the helix shape by external wave are also considered.
15:15 - 15:30 - Semiconductor-Based Nanostructures for Spectral Filtering Withdrawn [Show abstract]
  • Clément Maës, ONERA, France
We present a theoretical and experimental study of a nanostructured guided-mode resonant (GMR) spectral filter operating in the long-wave infrared (LWIR) wavelength range. The component is made of III-V semiconductors: heavily n-doped InAsSb for the grating and GaSb for the waveguide of the GMR resonator.
14:00 - Active and non-linear II (New Journal of Physics session)

Session chairperson(s): Michele Cotrufo

14:00 - 14:30 - Time-varying Route to Non-Foster Elements Invited oral [Show abstract]
  • Silvio Hrabar, University of Zagreb, Croatia
It is well-known that a non-Foster capacitance can be achieved by negative inversion of ordinary positive capacitor with the virtue of Negative Impedance Converter. Here, we propose an alternative way, based on appropriately modulated time-varying reactive element. The correctness of the basic idea is verified by circuit-theory simulation of time-varying-based non-Foster negative capacitor.
14:30 - 14:45 - Beamforming with Neural-Networked Programmable Metasurfaces Oral [Show abstract]
  • Stanislav Maslovski, Dept. of Electronics, Telecommunications and Informatics, University of Aveiro, Portugal
  • Abdelghafour Abraray, Instituto de Telecomunicações, Portugal
  • Nuno Carvalho, Dept. of Electronics, Telecommunications and Informatics, University of Aveiro, Portugal
  • Antonio Navarro, Dept. of Electronics, Telecommunications and Informatics, University of Aveiro, Portugal
In this presentation, we outline a novel architecture to enable intelligent, reconfigurable multibeam antennas for future device-to-device wireless communications. Two-dimensional metamaterials – metasurfaces – have been proposed for high-throughput microwave/millimeter and sub-millimeter band communications. Metasurfaces have emerged as versatile photonic tools for controlling wave fronts and performing nearly-instantaneous operations on the angular spectrum of propagating electromagnetic waves. Our aim is to implement the signal processing and control associated with the formation and tracking of the communication beams within the smart, programmable metasurface layers. Offsetting a part of such processing from the silicon to the quasi-optical metasurface layers shall result in reduction of the computational overheads, which is required when dealing with the evergrowing throughput needs for future telecommunications.
14:45 - 15:00 - Enhanced Photon-Pair Generation Through Extended Bound-State Resonances In Nonlinear Metasurfaces Oral [Show abstract]
  • Andrea Mazzanti, Politecnico di Milano, Italy
  • Matthew Parry, Australian National University, Australia
  • Alexander Poddubny, Ioffe Physical Technical Institute, Russia
  • Giuseppe Della Valle, Politecnico di Milano, Italy
  • Dragomir Neshev, Australian National University, Australia
  • Andrey Sukhorukov, Australian National University, Australia
We predict a strong enhancement of quantum photon-pair generation through spontaneous parametric down-conversion in a quadratically nonlinear metasurface with a one-dimensional periodicity. Our metasurface supports bound states in the continuum at the emission wavelengths. We establish the experimental conditions for tailoring of the bi-photon spatial and frequency spectra associated with quantum entanglement.
15:00 - 15:15 - A Fixed-Frequency Reconfigurable Holographic Leaky-Wave Antenna for Dynamically-Controlled Radiation Patterns Oral [Show abstract]
  • Min Seok Kim, University of Toronto, Canada
  • George Eleftheriades, University of Toronto, Canada
This work proposes a reconfigurable holographic leaky-wave antenna that offers independent and dynamic control over (i) the radiation angle (including broadside) and (ii) the radiation rate at the fixed operation frequency of 5 GHz. This is achieved by leveraging the theory of binary holography and utilizing a tunable Huygens’ metasurface as a reconfigurable holographic surface. We present a route to the physical realization of the proposed reconfigurable leaky-wave antenna and numerically verify its versatile scanning properties via full-wave simulations.
15:15 - 15:30 - Huygens'-metasurface-assisted Reconfigurable Leaky-Wave Antennas with Dynamically-Controlled Radiation Patterns Oral [Show abstract]
  • Min Seok Kim, University of Toronto, Canada
  • George Eleftheriades, University of Toronto, Canada
This work proposes a reconfigurable leaky-wave antenna that can independently control (i) the radiation angle (including broadside), (ii) leakage constant, and (iii) phase constant of a guided mode at the fixed operation frequency of 5 GHz. This is achieved by incorporating a tunable omega-bianisotropic Huygens' metasurface in the design of a leaky-wave antenna. In particular, the tunable Huygens’ metasurface is synthesized by cascading four reconfigurable impedance layers to dynamically control the constitutive parameters of the Huygens' metasurface, thereby eliminating unwanted Floquet modes and the open-stopband effect. The versatile scanning capability of the proposed reconfigurable leaky-wave antenna is numerically studied based on full-wave simulations.
15:30 - 15:45 - Reflective Limiters Based on EP Degeneracies Oral [Show abstract]
  • Suwun Suwunnarat, Wesleyan University, USA
  • Rodion Kononchuk, Wesleyan University, USA
  • Andrey Chabanov, University of Texas at San Antonio, USA
  • Ilya Vitebskiy, Air Force Research Laboratory, Sensors Directorate, Wright-Patterson Air Force Base, USA
  • Nicholaos Limberopoulos, Air Force Research Laboratory, Sensors Directorate, Wright-Patterson Air Force Base, USA
  • Tsampikos Kottos, Wesleyan University, USA
We propose a photonic limiter operating at exceptional point degeneracies (EPD). At low-power radiation it demonstrates an EPD-based high transmittance. At high-power radiation the transmittance is abruptly suppressed, due to a self-induced lift of EPD.
15:45 - 16:00 - Optimization of Phase Change Material-based Reconfigurable Meta-devices Oral [Show abstract]
  • Sawyer D. Campbell, Penn State University, USA
  • Yuhao Wu, Penn State University, USA
  • Eric B. Whiting, Penn State University, USA
  • Ronald. P. Jenkins, Penn State University, USA
  • Douglas H. Werner, Penn State University, USA
Reconfigurable meta-devices have the potential to disrupt conventional optical elements by offering both the exotic performances of metamaterials and a pathway to all-optical or electrical tuning. To this end, phase change chalcogenide materials represent one of the most promising platforms for realizing truly disruptive optical performances. However, it remains a challenge to design meta-devices that fully exploit the range in permittivity that these phase change materials offer. To this end, multi-objective optimization algorithms are perfectly suited to maximizing the performances of reconfigurable meta-devices.
14:00 - Mechanical and elastic metamaterials I

Session chairperson(s): Seunghwi Kim

14:00 - 14:30 - Recent Progress on 3D Chiral Mechanical Metamaterials Invited oral [Show abstract]
  • Martin Wegener, Institute of Applied Physics and Institute of Nanotechnology, Karlsruhe Institute of Technology (KIT), Germany
We review our recent progress on three-dimensional (3D) chiral mechanical metamaterials in the linear elastic regime. This includes ultrasound experiments on acoustical activity with transient nanometer-precision displacement-detection, the mapping of this behavior (as well as of the static behavior) onto effective-medium descriptions beyond Cauchy elasticity, the possibility of isotropic acoustical activity in rationally designed 3D chiral quasi-crystalline mechanical metamaterials, and early work on the possibility of using 3D chiral mechanical metamaterials for high-frequency gravitational-wave detection.
14:30 - 14:45 - An Active Mechanical Willis Meta-Layer with Asymmetric Polarizabilities Oral [Show abstract]
  • Guoliang Huang, University of Missouri, USA
  • Yangyang Chen, University of Missouri, United States
  • Xiaopeng Li, University of Missouri, United States
  • Michael Haberman, University of Texas at Austin, United States
This work introduces an active scatterer in a mechanical meta-layer that exploits piezoelectric sensor-actuator-pairs controlled by digital circuits. We experimentally demonstrate abilities of the mechanical Willis meta-layer, in beams and plates, for independently engineering transmission and reflection coefficients of flexural waves in both amplitude and phase and nonreciprocal wave propagations.
14:45 - 15:00 - Isotoxal-Star-Based Auxetic Micro-Lattice For Wide-Band Three-Dimensional Elastic Wave Attenuation Oral [Show abstract]
  • Nikhil JRK Gerard, North Carolina State University, USA
  • Mourad Oudich, The Pennsylvania State University, USA
  • Huachen Cui, University of California Los Angeles, USA
  • Zhenpeng Xu, University of California Los Angeles, USA
  • Xiaoyu Zheng, University of California Los Angeles, USA
  • Yun Jing, The Pennsylvania State University, USA
This work puts forward the design, fabrication and experimental characterization of a lightweight three-dimensional micro-lattice-based elastic metamaterial. Alongside being equipped with wide tailorable bandgaps in all directions of propagation, the material also possesses the second order functionality of exhibiting a negative Poisson's ratio
15:00 - 15:15 - Modelling of Elastic Metamaterials with Multiple Local Resonators Oral [Show abstract]
  • Zhengwei Li, University of Alberta, Canada
  • Xiaodong Wang, University of Alberta, Canada
In this study, a new elastic metamaterial featuring multiple local resonators has been developed with negative effective mass and/or negative effective modulus. An illustrative example is presented to show the corresponding influence of the multiple local resonances. The current method opens a novel route to design elastic metamaterials by fully exploring the effect of multiple local resonances on the double negative behaviour featuring negative phase velocity, as well as the single negative behaviour featuring wave attenuation.
15:15 - 15:30 - Mechanically Actuated Acoustic Wave Propagation Modification by Tailoring of Equifrequency Contour of a Phononic Metamaterial Oral [Show abstract]
  • Arup Neogi, University of North Texas, USA
  • Hyepnu Heo, University of North Texas, USA
  • Arkadii Krokhin, University of North Texas, USA
  • Ezekiel Walker, University of North Texas, USA
  • Jaeyung Ju, Shanghai JiaoTong University-University of Michigan, China
– Mechanically actuated a phononic metamaterial underwater is proposed for the active control of the transmission of sound waves and demonstrated through numerical simulation and experiments. The phononic crystal consists of passive asymmetric scatterers with the active mechanical control system of the rotation of the individual scatterer. The rotation of the individual scattering elements of the phononic crystal is able to provide the modification of the equifrequency contour resulting in a different mode of propagation of the ultrasonic waves. The tunability of the phononic crystal allows for dynamic switching between an acoustically conducting state to an insulating state of the phononic device. Furthermore, it can be used as an active acoustic filter or lens.
14:00 - Special session: Adaptive EM skins for smart environment

Organizer(s): Paolo Rocca; Marco Salucci

Session chairperson(s): Younes Ra'di

14:00 - 14:15 - From Advanced Cloaking Metasurfaces to a New Generation of Intelligent Antennas Oral [Show abstract]
  • Mirko Barbuto, “Niccolò Cusano” University, Italy
  • Angelica Viola Marini, ROMA TRE University, Italy
  • Alessio Monti, “Niccolò Cusano” University, Italy
  • Davide Ramaccia, ROMA TRE University, Italy
  • Stefano Vellucci, University of Trento, Italy
  • Alessandro Toscano, ROMA TRE University, Italy
  • Filiberto Bilotti, ROMA TRE University, Italy
In this work, we review our recent research on advanced cloaking metasurfaces used to cover monopole antennas. Cloaking devices based on passive metasurfaces have demonstrated a dramatic enhancement of the antenna functionalities, thanks to the additional the degrees of freedom available in the design. Integrating electronic circuits and enabling time modulation in cloaking metasurfaces can further lead to more advanced functionalities, making the covered antennas ever more intelligent. In this framework, our vision is to extensively use reconfigurable metasurfaces to make the antennas cognitive and adaptive, enabling sensing capabilities of the surrounding electromagnetic environment, and dynamic changing of their properties (e.g. operation frequency, visibility/invisibility, polarization, radiation pattern shape, power level, etc.) accordingly.
14:15 - 14:45 - Path-Loss Modeling for Reconfigurable Intelligent Meta-Surfaces in Smart Radio Environments – Theory and Experimental Validation Invited oral [Show abstract]
  • Marco Di Renzo, Paris-Saclay Univ. / CNRS, France
In this paper, we will report recent results that are aimed at characterizing the path-loss of reconfigurable intelligent meta-surfaces by using theory and experiments.
14:45 - 15:00 - Smart EM Environment as Enabling Technology for Future Wireless Systems Oral [Show abstract]
  • Marco Salucci, ELEDIA Research Center, University of Trento, Italy
  • Baozhu Li, Nanjing Normal University, China
  • Arianna Benoni, ELEDIA Research Center, University of Trento, Italy
  • Paolo Rocca, ELEDIA Research Center, University of Trento, Italy
  • Andrea Massa, ELEDIA Research Center, University of Trento, Italy
An innovative approach for the design of future-generation communication systems is proposed aimed at synthesizing a user-defined field distribution in a given domain by opportunistically exploiting the complex scattering environment in which both primary source and receiving terminals operate.
15:00 - 15:15 - Time-Modulated EM Surfaces for Next-Generation Communications and Sensing Oral [Show abstract]
  • Lorenzo Poli, ELEDIA Research Center, University of Trento, Italy
  • Paolo Rocca, ELEDIA Research Center, University of Trento, Italy
This work is aimed at presenting an overview on how the time-modulation strategy has been applied to the design and control of antenna systems, until its recent consideration in time-modulated EM surfaces.
14:00 - Metamaterial and metasurface antennas I

Session chairperson(s): Adam Overvig

14:00 - 14:30 - Topological Phenomena in Antenna Systems Invited oral [Show abstract]
  • Mirko Barbuto, Niccolò Cusano University, Italy
  • Mohammad-Ali Miri, City University of New York, USA
  • Andrea Alù, City University of New York, USA
  • Filiberto Bilotti, ROMA TRE University, Italy
  • Alessandro Toscano, ROMA TRE University, Italy
Topological concepts have found several applications in different branches of physics. As a notable example at microwave frequencies, in this contribution, we focus on the topological properties of phase singularity points of vortex modes, which can be generated by using higher order modes of patch antennas. In particular, we report our recent results on the possibilities offered by structured fields, i.e. the collinear superposition of vortex modes with different topological charges, for designing radiating systems with novel or enhanced functionalities.
14:30 - 15:00 - Nonreciprocal Phased-Array Antennas: Theory and Experiments Invited oral [Show abstract]
  • J. Sebastian Gomez Diaz, University of California, Davis, USA
  • Jiawei Zhang , China Academy of Information and Communication Technology, China
  • James Do , University of California, Davis, USA
  • Mark Bourkov, University of California, Davis, USA
  • Alejandro Alvarez-Melcon, Technical University of Cartagena, Spain
This talk describes the concept, theory, and experimental demonstration of phased-array antennas able to exhibit exciting nonreciprocal functionalities, including (i) an independent control of their transmission and reception patterns at the same operation frequency; and (ii) the ability of transmit and receive waves with opposite polarization states. The approach is based on combining time-modulated resonators with high-Q radiating elements and then exploiting the Aharonov-Bohm effect to manipulate the phase of the transmitted and received waves in a nonreciprocal manner. This technique can be applied to develop efficient nonreciprocal phased-array antennas across the electromagnetic spectrum and find broad applications in wireless communication system as well as in polarimetric radars and sensors.
15:00 - 15:15 - Experimental Demonstration of Non-Foster Self-oscillating Huygens Radiator Oral [Show abstract]
  • Leo Vincelj, University of Zagreb Faculty of electrical engineering and computing, Croatia
  • Richard W. Ziolkowski, University of Technology Sydney, 81 Broadway, Ultimo 2007, Australia
  • Silvio Hrabar, University of Zagreb Faculty of electrical engineering and computing, Croatia
An extension of the basic concept of a self-oscillating non-Foster cross-dipole to a self-oscillating Huygens radiator has been developed theoretically and studied numerically. A proof-of-concept prototype has been built. The preliminary results have demonstrated self-oscillations with nearly-perfect admittance matching over a tuning bandwidth of 1:1.35.
15:15 - 15:30 - Self-Matched Wideband Topological Antenna Withdrawn [Show abstract]
  • Shreya Singh, University of California, San Diego, USA
  • Dia'aaldin Bisharat, University of Califonia, San Diego, USA
  • Dan Sievenpiper, University of California, San Diego, USA
This work focuses on introducing a novel application of topological insulators in the form of self matched antennas. Self-matching is a property of the topological antenna that leads it to be resistant to any reflection caused by the impedance mismatch at the truncation of the metasurface topological structure with free space. This behavior can be attributed to the spin-momentum locking property of topological insulators and removes the need for any matching networks or flaring ends to promote a gradual impedance mismatch. The proposed implementation provides a 30\% bandwidth with a return loss ranging between -15 to -22 dB in the operating bandwidth and a radiation efficiency of over 98.4%.
15:30 - 16:00 - Coffee Break (Tuesday Afternoon)
16:00 - 18:00 - Oral Sessions (Tuesday Afternoon 2)
16:00 - Special session: Theory and applications of exceptional points

Organizer(s): Filippo Capolino

Session chairperson(s): Diana Strickland

16:00 - 16:15 - The Stability of Optical Clusters Explained Using Exceptional Point Physics Oral [Show abstract]
  • Xiao LI, The Hong Kong University of Science and Technology, Hong Kong
Optical force can stably bind multiple microparticles into an optical matter. However, we discovered that the Lorentz force alone can bind only a small number of particles and the optical cluster always becomes unstable when the particle number or the dielectric constant of the particles increases beyond a certain critical point. The instability can be explained as the consequence of an open system always possesses exceptional points.
16:15 - 16:30 - Sensing Via Exceptional Points in Space and Time Periodic Systems and in PT-Symmetric Systems Oral [Show abstract]
  • Mohamed Nada, University of California, Irvine (UCI), USA
  • Tarek Mealy, University of California, Irvine (UCI), United States
  • Ehsan Hafezi, University of California, Irvine (UCI), USA
  • Alireza Nikzamir, University of California, Irvine (UCI), USA
  • Filippo Capolino, University of California, Irvine (UCI), USA
<p> We review and explore sensor applications based on electromagnetic systems operating near an exceptional point of degeneracy (EPD). The EPD is defined as the point at which the system eigenmodes coalesce in both their eigenvalues and eigenvectors varying a system parameter. Sensors based on EPDs show sensitivity proportional to δ^1/m, where δ is a perturbation of a system parameter and m is the order of the EPD. EPDs manifest in PT-symmetric systems or periodic systems that can be periodic in either time or space. We review all the methods to obtain EPD based sensors, and we focus on two classes of ultra-sensitive EPD systems: i) periodic linear time-varying single oscillators, and ii) optical gyroscopes based on a modified coupled resonators optical waveguide (CROW) exhibiting 4th order EPD.</p>
16:30 - 17:00 - Robust Scattered Fields from Adiabatically Driven Targets around Exceptional Points Extended oral [Show abstract]
  • TSAMPIKOS KOTTOS, WESLEYAN UNIVERSITY, USA
  • Lucas Fernandez-Alcazar, WESLEYAN UNIVERSITY, United States
  • Huanan Li, ASRC, CUNY, United States
  • Fred Ellis, Wesleyan University, United States
  • Andrea Alu, ASRC, CUNY, United States
We show that a wave scattered wave from a time-modulated target, encircling quasi-adiabatically an exceptional point in a parameter space, can be robust to variations of the incident field and local operational details of the driving. This insensitivity is abruptly suppressed for scattering dwell times smaller than a critical value.
17:00 - 17:15 - Exceptional Points in the Truly Quantum Domain: Challenges and Opportunities Oral [Show abstract]
  • Yogesh Joglekar, Indiana University Purdue University Indianapolis (IUPUI), USA
Exceptional points (EPs) are degeneracies of non-Hermitian Hamiltonians where both eigenvalues and corresponding eigenvectors coalesce. Over the past five years, EPs in open wave systems with gain, loss, or both, have been intensely explored due to their topological properties and enhanced sensitivity. In this classical domain (the number of energy quanta is much larger than one), the non-unitary dynamics of a system are accurately described by an effective, non-Hermitian Hamiltonian. In contrast, the dynamics of a minimal quantum system, inevitably coupled to the environment, are described by a Lindblad equation for its density matrix. I will review the challenges for realizing a quantum system that undergoes the non- unitary, coherent time evolution generated by a non-Hermitian Hamiltonian, or more generally, parity-time symmetric quantum systems. I will then show how these challenges can be overcome in multiple platforms comprising ultracold atoms, integrated or table-top quantum photonics, and superconducting qubits.
17:15 - 17:30 - Accelerometers Based on Exceptional Points Oral [Show abstract]
  • Rodion Kononchuk, Wave Transport in Complex Systems Lab, Department of Physics, Wesleyan University, USA
  • Tsampikos Kottos, Wave Transport in Complex Systems Lab, Department of Physics, Wesleyan University, USA
We propose a parity-time symmetric accelerometer that involves a micromechanical spring-mass coupled to a photonic circuit which is tuned at exceptional-point degeneracy. Spring-mass response to acceleration leads to square-root circuit’s resonance detuning, enhancing the probe of ultra-small accelerations. Our design provides a pathway towards new generation of hypersensitive accelerometers/vibrometers.
17:30 - 17:45 - Enhancing Light-Matter Interactions at Non-Hermitian Degeneracies Oral [Show abstract]
  • S.K. Ozdemir, The Pennsylvania State University, USA
Spectral degeneracies, known as exceptional points, in open quantum systems exhibit rich physics and promise new advances in controlling wave transport and enhancing lightmatter interactions. In this talk, we will discuss exceptional points emerging from asymmetric coupling between the modes of a physical system, and present two examples on how such chiral exceptional points lead to enhanced sensor’s response [1]-[2], and to quantum processes that stem solely from their presence in a nonlinear photonic system [3].
17:45 - 18:15 - Onset of Synchronization at Exceptional Points Invited oral [Show abstract]
  • Mohammad-Ali Miri, Queens College of CUNY, USA
Frequency synchronization of two coupled lasers with initially detuned frequencies is investigated using a second-order nonlinear oscillator model. It is shown that the two lasers have a better tendency to synchronize when their interaction is of dissipative nature. In this case, the onset of synchronization is found to be at an exceptional point singularity.
16:00 - Active and non-linear III (New Journal of Physics session)

Session chairperson(s): Michele Cotrufo

16:00 - 16:30 - Electro-optically Modulated Reflective and Transmissive Metasurfaces Invited oral [Show abstract]
  • Ali Forouzmand, Northeastern University, USA
  • Hossein Mosallaei, Northeastern University, USA
We propose several dynamic optical platforms based on gate-tunable biasing and integration of indium-tin-oxide and doped-semiconductors into all-dielectric/plasmonic metasurfaces. Besides the widely-utilized gap-plasmon and Mie-type resonances to enhance the light-matter interaction, we focus on the excitation of guided-mode and Fabry-Pérot-type resonances with relatively higher quality-factors. This helps to achieve highly-efficient tunable reflective and transmissive metasurfaces in near-infrared regime.
16:30 - 16:45 - Perfect Absorption in a Metasurface-Programmable Complex Scattering Enclosure Oral [Show abstract]
  • Philipp del Hougne, Institut d’Electronique et de Télécommunications de Rennes, France
  • Mohammadreza F. Imani, Department of Electrical and Computer Engineering, Duke University, USA
  • David R. Smith, Department of Electrical and Computer Engineering, Duke University,, USA
Achieving perfect absorption (PA) in a complex scattering enclosure recently attracted much attention thanks to its large potential for applications in analog signal processing, energy transfer, precision sensing, secure communication and random lasing. Current schemes rely on shaping multiple incident wave fronts to achieve coherent PA. Here, we introduce an alternative route by tweaking the randomness of the medium itself. In our experiment, we use a programmable metasurface to reconfigure the boundary conditions of a chaotic cavity. We systematically analyze achievability and sensitivity of the PA condition. Our scheme can also be applied to other types of wave phenomena, e.g. in photonic or phononic systems.
16:45 - 17:00 - Third Harmonic Wavefront Control and Multiplexed Holography with a Pancharatnam-Berry Phase Silicon Metasurface Oral [Show abstract]
  • Bernhard Reineke, Paderborn University, Germany
  • Basudeb Sain, Paderborn University, Germany
  • Ruizhe Zhao, Beijing Institute of Technology, China
  • Luca Carletti, University of Padova, Italy
  • Bingyi Liu, Harbin Institute of Technology, China
  • Lingling Huang, Beijing Institute of Technology, China
  • Costantino De Angelis, University of Brescia, Italy
  • Thomas Zentgraf, Paderborn University, Germany
Dielectric nonlinear optical metasurfaces show an unprecedented potential to realize optical applications like nonlinear vortex beam generation or multiplexed holography. Therefore, all-dielectric metasurfaces have been used to realize a plethora of nonlinear optical experiments, like wave mixing or efficient higher harmonic generation. Here, we present a nonlinear silicon metasurface for third harmonic wavefront control.
17:00 - 17:15 - Averaged Power of Multitone Wave Packets and Mixing Products Oral [Show abstract]
  • Alex Schuchinsky, University of Liverpool, United Kingdom
The properties of multitone wave packets and products of their nonlinear mixing are discussed. An average power is obtained for wave packets with a finite number Nc of carriers and their mixing products. Distinctive features of nonlinear products generated by wave packets are illustrated for harmonic signals with Gaussian envelopes.
17:15 - 17:30 - Circularly Polarized Third Harmonic Generation in Vacuum Ultraviolet Region Using Square Lattice Photonic Crystal Nanomembrane Oral [Show abstract]
  • Kuniaki Konishi, The University of Tokyo, Japan
  • Daisuke Akai, Toyohashi University of Technology, Japan
  • Yoshio Mita, The University of Tokyo, Japan
  • Makoto Ishida, Toyohashi University of Technology, Japan
  • Junji Yumoto, The University of Tokyo, Japan
  • Makoto Kuwata-Gonokami, The University of Tokyo, Japan
We demonstrate that a waveguide resonance of free-standing dielectric photonic crystal nanomembrane with the four-fold rotational symmetry allows the circularly-polarized third harmonic generation in vacuum ultraviolet region at 157 nm with sufficient intensity for VUV spectroscopy.
17:30 - 17:45 - Nano-Structures in Lithium Niobate for Electro-Optic Switching Oral [Show abstract]
  • Helena Weigand, ETH Zurich, Switzerland
  • Flavia Timpu, ETH Zurich, Switzerland
  • Fabian Kaufmann, ETH Zurich, Switzerland
  • Felix Richter, ETH Zurich, Switzerland
  • Viola Vogler-Neuling, ETH Zurich, Switzerland
  • Artemios Karvounis, ETH Zurich, Switzerland
  • Rachel Grange, ETH Zurich, Switzerland
We demonstrate the fabrication of nano-structures from lithium niobate thin films and investigate their optical resonances in the visible and near-infrared region. The large electro-optic coefficient of LiNbO3 offers a platform for active tuning of transmission properties in deeply subwavelength films.
17:45 - 18:00 - Linear Frequency Conversion In Three- And Two-dimensional Geometries Withdrawn [Show abstract]
  • Vincent Ginis, Vrije Universiteit Brussel / Harvard University, USA
  • Hannah Pinson, Vrije Universiteit Brussel, Belgium
We give an overview of our work on shifting of frequencies using linear, time-dependent structures. We discuss both the three-dimensional and the two-dimensional case and indicate the differences in the performance of the structures.
16:00 - Special session: Intense-field nanophotonics

Organizer(s): Maxim Shcherbakov; Gennady Shvets

Session chairperson(s): Francesco Monticone

16:00 - 16:15 - Ultrafast Diffraction Switching in GaAs Metasurfaces using Quadrupole Resonances Oral [Show abstract]
  • Polina Vabishchevich, Sandia National Laboratories, USA
  • Alexandr Vaskin, Institute of Applied Physics, Abbe Center of Photonics, Friedrich Schiller University Jena, Albert-Einstein-Str. 15, 07745 Jena, Germany
  • Nick Karl, Sandia National Laboratories, USA
  • John Reno, Sandia National Laboratories, USA
  • Michael Sinclair, Sandia National Laboratories, USA
  • Isabelle Staude, Institute of Applied Physics, Abbe Center of Photonics, Friedrich Schiller University Jena, Albert-Einstein-Str. 15, 07745 Jena, Germany
  • Igal Brener, Sandia National Laboratories, USA
We use GaAs-based metasurface operating at its magnetic quadrupole resonance to switch the -1 diffraction order. We design suppression of radiation in the diffraction direction and tune it with 2.5 ps modulation time using optical pumping.
16:15 - 16:30 - Frequency Conversion in a Dielectric Time-Variant Metasurface Oral [Show abstract]
  • Nicholas Karl, Sandia National Laboratories, USA
  • Polina Vabishchevich, Sandia National Laboratories, USA
  • Maxim Shcherbakov, Cornell University, USA
  • Sheng Liu, Sandia National Laboratories, USA
  • Michael Sinclair, Sandia National Laboratories, USA
  • Gennady Shvets, Cornell University, USA
  • Igal Brener, Sandia National Laboratories, USA
We experimentally observe frequency conversion via electromagnetic wave interaction with a high quality-factor resonance in an array of resonators whose refractive indices are varied on an ultrafast timescale. Further, we describe the observations using coupled mode theory.
16:30 - 16:45 - Chirp-sensitive Response of Nonlinear Semiconductor Metasurfaces Oral [Show abstract]
  • Giovanni Sartorello, Cornell University, USA
  • Maxim Shcherbakov, Cornell University, USA
  • Zhiyuan Fan, Cornell University, USA
  • Robert Schwartz, University of Maryland, USA
  • Daniel Woodbury, University of Maryland, USA
  • Howard Milchberg, University of Maryland, USA
  • Gennady Shvets, Cornell University, USA
Time-variant semiconductor resonators have attracted interest for non-reciprocity and applications in frequency conversion and the photon acceleration regime. Here, we control the nonlinear response of time-variant metasurfaces by changing the pulse chirp of the incident fundamental, with both the magnitude and sign of the chirp affecting the third harmonic generation spectrum.
16:45 - 17:00 - Beating Absorption in Solid-State High Harmonics Oral [Show abstract]
  • Giulio Vampa, Stanford PULSE Institute, USA
  • Hanzhe Liu, Stanford PULSE Institute; Department of Physics, Stanford University, USA
  • Jingyuan Linda Zhang, Department of Applied Physics, Stanford University; E. L. Ginzton Laboratory, Stanford University; Department of Electrical Engineering, Stanford University, USA
  • Yu Shi, E. L. Ginzton Laboratory, Stanford University; Department of Electrical Engineering, Stanford University, USA
  • Siddharth Buddhiraju, E. L. Ginzton Laboratory, Stanford University; Department of Electrical Engineering, Stanford University, USA
  • Shanhui Fan, Department of Applied Physics, Stanford University; E. L. Ginzton Laboratory, Stanford University; Department of Electrical Engineering, Stanford University, USA
  • Jelena Vuckovic, Department of Applied Physics, Stanford University; E. L. Ginzton Laboratory, Stanford University; Department of Electrical Engineering, Stanford University, USA
  • Philip H. Bucksbaum, Stanford PULSE Institute; Department of Physics, Stanford University; Department of Applied Physics, Stanford University; Department of Photon Science, Stanford University, USA
  • David A. Reis, Stanford PULSE Institute; Department of Applied Physics, Stanford University; Department of Photon Science, Stanford University, USA
We overcome material absorption of high harmonics generated from a silicon crystal by generating them from a periodic array of thin one-dimensional crystalline silicon ridge waveguides. Adding vacuum gaps between the ridges avoids the high absorption loss of the bulk and results in a ~ 100-fold increase of the extraction depth. Looking ahead, our results enable bright on-chip coherent short-wavelength sources and may extend the usable spectral range of traditional nonlinear crystals to their absorption windows.
17:00 - 17:15 - Tunable Second Harmonic Generation In AlGaAs Metasurface Through Reconfigurable Liquid Crystal Oral [Show abstract]
  • Davide Rocco, University of Brescia, Italy
  • Luca Carletti, University of Padova, Italy
  • Roberto Caputo, University of Calabria, Italy
  • Marco Finazzi, Politecnico di Milano, Italy
  • Michele Celebrano, Politecnico di Milano, Italy
  • Costantino De Angelis, University of Brescia, Italy
we study the directionality of the second harmonic (SH) signal emitted by a dielectric metasurface made of AlGaAs nanodisks embedded into a liquid crystal matrix. Notably, we numerically demonstrate the modulation of the SH total power and the emission pattern signal coming from the proposed metasurface as a function of the liquid crystal orientation.
17:15 - 17:30 - Deep Optical Switching on Subpicosecond Timescales in an Amorphous Ge Metamaterial Oral [Show abstract]
  • Robert Lemasters, Emory University, USA
  • Maxim Shcherbakov, Cornell University, USA
  • Guoce Yang, Emory Univerity, USA
  • Zhiyuan Fan, Cornell University, USA
  • Jia Song, Emory University, USA
  • Tianquan Lian, Emory University, USA
  • Hayk Harutyunyan, Emory University, USA
  • Gennady Shvets, Cornell University, USA
Pump-probe measurements are performed on amorphous Ge based micro-resonator metasurfaces which exhibit strong photonic resonant modes in the mid infrared. We observe a 51% (0.31 OD) change in transmittance signal modulation depth with subpicosecond modulation speed. This is obtained with pump fluences P < 204 uJ=cm^2.
17:30 - 17:45 - Time-dependent Metasurfaces for Tunable Broadband Harmonics Generation Oral [Show abstract]
  • Varvara Zubyuk, Lomonosov Moscow State University, Russia
  • Pavel Shafirin, Lomonosov Moscow State University, Russia
  • Alexander Shorokhov, Lomonosov Moscow State University, Russia
  • Alexander Musorin, Lomonosov Moscow State University, Russia
  • Tatyana Dolgova, Lomonosov Moscow State University, Russia
  • Gennady Shvets, Cornell University, USA
  • Maxim Shcherbakov, Lomonosov Moscow State University, Russia
  • Andrey Fedyanin, Lomonosov Moscow State University, Russia
The possibility of controlling the spectrum of the generated third harmonic for high quality-factor resonant metasurfaces is examined. The ultrafast dynamics for both fundamental wavelength and third harmonic generation is observed in all-dielectric metasurfaces with pump-probe technique.
17:45 - 18:00 - Tailoring Nonlinear Diffraction In Silicon Metasurfaces Oral [Show abstract]
  • Andrea Tognazzi, Università degli Studi Di Brescia, National Institute of Optics, Italy
  • Kirill Okhlopkov, Lomonosov Moscow State University, Russia
  • Attilio Zilli, Department of Physics, Politecnico di Milano, Italy
  • Davide Rocco, Università degli Studi Di Brescia, National Institute of Optics, Italy
  • Luca Fagiani, Consiglio Nazionale delle Ricerche LNESS Laboratory, Italy
  • Erfan Mafakheri, Consiglio Nazionale delle Ricerche LNESS Laboratory, Italy
  • Monica Bollani, Consiglio Nazionale delle Ricerche LNESS Laboratory, Italy
  • Marco Finazzi, Department of Physics, Politecnico di Milano, Italy
  • Michele Celebrano, Department of Physics, Politecnico di Milano, Italy
  • Maxim Shcherbakov, Lomonosov Moscow State University, Russia
  • Andrey Fedyanin, Lomonosov Moscow State University, Italy
  • Costantino De Angelis, Università degli Studi Di Brescia, National Institute of Optics, Italy
In this work we propose a high-quality factor semiconductor nanoparticles array made of rectangular silicon nanobricks. Our optimized metasurface can dramatically boost third harmonic generation, with a complex polarization dependence in the different diffraction orders.
16:00 - Time-space modulating metasurfaces

Session chairperson(s): Robert Duggan

16:00 - 16:30 - Recent Advances in Space-Time-Coding Digital Metasurfaces Invited oral [Show abstract]
  • Vincenzo Galdi, University of Sannio, Italy
  • Lei Zhang, Southeast University, China
  • Xiao Q. Chen, Southeast University, China
  • Rui W. Shao, Southeast University, China
  • Jun Y. Dai, Southeast University, China
  • Qiang Cheng, Southeast University, China
  • Massimo Moccia, University of Sannio, Italy
  • Giuseppe Castaldi, University of Sannio, Italy
  • Tie Jun Cui, Southeast University, China
We provide a compact summary of our recent results and ongoing research on digital metasurfaces based on spatio-temporal coding. Examples of field manipulations include harmonic beam steering and/or shaping and programmable nonreciprocal effects. Possible applications range from wireless communications to radars and imaging.
16:30 - 16:45 - Dynamical Metasurfaces: Luminal Amplification and Temporal Wood Anomalies Oral [Show abstract]
  • Emanuele Galiffi, Imperial College London, United Kingdom
  • Paloma A. Huidobro, Instituto de Telecomunicações, Instituto Superior Técnico, Lisbon, Portugal
  • Andrea Alù, CUNY Advanced Science Research Center, USA
  • John Pendry, Imperial College London, UK
Dynamical modulation of the optical properties of thin films promises to open new avenues for wave control. We present two new opportunities enabled by time-modulation for surface-wave control: (1) Luminal amplification, namely the broadband generalisation of parametric amplification, and (2) Temporal Wood anomalies, namely the generalization of the Wood anomaly used in grating couplers to the time domain, enabling perfect coupling of radiation to surface waves while circumventing the need for surface structuring and near-field coupling schemes.
16:45 - 17:00 - Electromagnetic Boundary Conditions in Time Dependent Materials Oral [Show abstract]
  • Rebecca Seviour, University of Huddersfield, United Kingdom
  • Jonathan Gratus, University of Lancaster, United Kingdom
  • Paul Kinsler, University of Lancaster, United Kingdom
Electromagnetic time dependent media are materials whose constitutive relations vary in time. Most models assume a constant permittivity and permeability, to model loss it is natural to consider complex constitutive relations. We show this is unphysical, presenting the correct boundary conditions necessary for wave propagation in a time dependent media.
17:00 - 17:15 - Achieving Electromagnetic Isolation by using Up- and Down-converting Time-Varying Metasurfaces Oral [Show abstract]
  • Davide Ramaccia, Università degli Studi Roma Tre, Italy
  • Dimitrios L. Sounas, Wayne State University, Michigan (US)
  • Angelica Viola Marini, Università degli Studi Roma Tre, Italy
  • Alessandro Toscano, Università degli Studi Roma Tre, Italy
  • Filiberto Bilotti, Università degli Studi Roma Tre, Italy
In this contribution, we propose a magnet-less non-reciprocal isolating system based on time-varying metasurfaces. The system consists of a conventional frequency selective device placed between two time-varying metasurfaces, one for frequency up-conversion and one for down-conversion by the same amount. The overall reciprocity of the system is broken by exploiting the different scattering response from the embedded device when illuminated from opposite directions, since the two time-varying metasurfaces impart an opposite frequency conversion for the two directions of illumination. Note that the transmitted fields are always at the same frequency as for the incident one, since the metasurfaces cancel the frequency conversion of each other. This strategy can be successfully exploited for conceiving a new family of non-reciprocal isolating systems, based upon well studies conventional electromagnetic devices.
17:15 - 17:30 - Modified Floquet Boundary Condition for Open Boundary Problems with N-Path Symmetry Oral [Show abstract]
  • Cody Scarborough, University of Michigan, USA
  • Anthony Grbic, University of Michigan, USA
Space-time modulated structures have attracted substantial attention in the metamaterials community in recent years. Most physical realizations of space-time modulated systems consist of discrete unit cells that can be independently modulated. While these physical structures are often analyzed as continuously modulated media, consideration of the spatial discretization yields a more accurate model. Additionally, a finite unit cell size enables phenomena which do not arise in the continuum limit. In this paper, a relation between the fields in each unit cell (pixel) of a free-space N-path system is derived. The relation is incorporated into a method of moments solver to compute the scattered field from a space-time modulated metasurface.
17:30 - 17:45 - Retroreflective Subharmonic Frequency Translation with a Spatiotemporal Metasurface Oral [Show abstract]
  • Zhanni Wu, University of Michigan, USA
  • Cody Scarborough, University of Michigan, USA
  • Anthony Grbic, University of Michigan, USA
A reflective, dual-polarized, spatiotemporally modulated metasurface is reported at X-band frequencies. Each column of subwavelength unit cells on the experimental metasurface can be independently, temporally modulated. Here, we consider a space-time modulation where the time modulation of adjacent columns is staggered to realize a discretized traveling-wave modulation. We propose an analytical model of such a metasurface with discretized spatial modulation. It is shown that at certain incident angles, the metasurface can perform retroreflective subharmonic frequency translation: Doppler-like frequency translation to a higher-order frequency harmonic in retroreflection. By changing the temporal modulation waveform on each column, the retroreflected frequency harmonic can be controlled.
17:45 - 18:00 - Nonreciprocity in Uniform Time-Varying Materials Using Spatial Dispersion Oral [Show abstract]
  • Grigorii Ptitcyn, Aalto University, Finland
  • Xuchen Wang, Aalto University, Finland
  • Ana Diaz-Rubio, Aalto University, Finland
  • Victor Asadchy, Stanford University, USA
  • Mohammad Sajjad Mirmoosa, EPFL, Switzerland
  • Shanhui Fan, Stanford University, USA
  • Sergei Tretyakov, Aalto University, Finland
Conventionally, nonreciprocity in time-varying systems is achieved by exploiting both temporal and spatial modulations. In this paper, we introduce a concept of magnetless bianisotropic time-modulated systems that support nonreciprocal wave propagation at the fundamental frequency and use only uniform, solely temporal material modulations.
18:00 - 18:30 - Phase and Time Modulation of Metasurfaces Invited oral [Show abstract]
  • Harry Atwater, California Institute of Technology, USA
Abstract
16:00 - Millimeter wave/THz metamaterials and applications

Session chairperson(s): Younes Ra'di

16:00 - 16:30 - Metageometries for Communication and Sensing Devices at THz Invited oral [Show abstract]
  • Miguel Beruete, Universidad Pública de Navarra, Spain
  • Irati Jáuregui-López, Universidad Pública de Navarra, España
  • Alexia Moreno-Peñarrubia, Universidad Pública de Navarra, España
  • Sergei A. Kuznetsov, Novosibirsk State University, Russia
Metasurfaces have been crucial for the development of THz technology. The recently proposed “metageometries”, which consist in convoluted unit cell geometries, have been demonstrated to improve largely the performance of metasensors based on metaatoms. Here we present results that extend the reach of metageometries in two different lines of technological importance. A labyrinth metasensor for the detection of fungi and a zigzag half-wave plate with excellent performance, both operating at THz and with an extremely compact profile.
16:30 - 17:00 - Millimeter-Wave And Sub-THz Modulated Metasurface Antennas Invited oral [Show abstract]
  • David González Ovejero, Centre National de la Recherche Scientifique, France
  • Xavier Morvan, Université de Rennes 1, France
  • Laurent Le Coq, Université de Rennes 1, France
  • Olivier de Sagazan, Université de Rennes 1, France
Modulated metasurfaces (MTSs) have sprung up in the last decade as an attractive solution for wave guidance and radiation. More precisely, modulated MTS antennas stand out for providing an unprecedented control of the aperture fields with low-profile and lightweight structures. In this class of antennas, a surface-wave (SW) is gradually radiated, owing to its interaction with a modulated impedance boundary condition (IBC). This IBC is typically implemented in the microwave regime by several thousands of sub-wavelength patches printed on a grounded slab. However, dielectric losses may hinder the use of standard printed circuit board (PCB) technology at higher frequencies. In this paper, we will address this issue by introducing a new class of metal-only modulated MTS, which can be easily fabricated by additive manufacturing or micro-machining for millimeter-wave and sub-THz applications.
17:00 - 17:15 - Extraordinary Terahertz Transmission Beyond Symmetric Unit Cells: Frequency, Time and Method of Moments Analysis Oral [Show abstract]
  • Ajla Nekovic, University of Sarajevo, Bosnia and Herzegovina
  • Miguel Camacho, University of Pennsylvania, United States
  • Pavel Penchev, University of Birmingham, United Kingdom
  • Suzanna Freer, University of Birmingham, United Kingdom
  • Stefan Dimov, University of Birmingham, United Kingdom
  • Rafael R Boix, University of Seville, Spain
  • Miguel Navarro-Cia, University of Birmingham, United Kingdom
The transmission spectra of trun cated rectangular arrays of tilted subwavelength slots measured with quasi optical systems are far richer in terms of resonances than the customary circular and square subwavelength hole arrays measured at optics We provide a comprehensive experimental st udy of such asymmetric arrays combined with Method of Moments analysis to understand the underlying physics and to provide design guidelines.
17:15 - 17:30 - Ultra-Thin Spatial Phase Modulator for THz Applications based on Metasurface Hybridised with Liquid Crystal Oral [Show abstract]
  • Oleksandr Buchnev, University of Southampton, Optoelectronics Research Centre, United Kingdom
  • Nina Podoliak, University of Southampton, Mathematical Sciences, United Kingdom
  • Korbinian Kaltenecker, Ludwig-Maximilians-University of Munich, Department of Physics, Germany
  • Markus Walther, University of Freiburg, Department of Molecular and Optical Physics, Germany
  • Vassili Fedotov, University of Southampton, Optoelectronics Research Centre, United Kingdom
We propose and experimentally demonstrate a concept of an ultra-thin spatial phase modulator (SPM) for correcting THz wavefronts. It exploits a combination of spatially addressable metasurfaces and an optically thin low-voltage liquid crystal cell. Our metadevice allows ‘imprinting’ 2D phase profile of any spatial complexity with a sub-wavelength spatial resolution, and can be readily fabricated using the well-established LC-device technology and high-resolution photolithography technique.
17:30 - 17:45 - Highly Transmissive Metasurfaces for Mm-wave Antenna Applications Oral [Show abstract]
  • Andreas Olk, IEE S.A., Luxembourg
  • David Powell, University of New South Wales, Sydney, Australia
In this contribution, we present our recent progress on mm-wave metasurface based antennas. We review synthesis and simulation techniques that enable highly efficient metasurfaces for the operation at W-band frequencies (75-110 GHz) and higher. Additionally, we present the design and characterization of a W-band switched beam antenna. We use high resolution near-field scanning to determine the phase focal point of the metasurface as well as the transmission efficiency. Switched beam functionality is demonstrated using far-field measurements with a bistatic system.
17:45 - 18:00 - Design of an Inverted Luneburg Lens by Metal-Only Metasurface Oral [Show abstract]
  • Jorge Ruiz-García, IETR, France
  • Enrica Martini, University of Siena, Italy
  • Cristian Della Giovampaola, Wave Up, Italy
  • Ronan Sauleau, Université de Rennes 1 - IETR, France
  • David González-Ovejero, CNRS - IETR, France
  • Stefano Maci, University of Siena, Italy
In this paper, we present the implementation of a new surface wave lens for beam-forming applications. The Flat Optics theory and a double-layered configuration are employed to create a plane wave with modifiable direction in the entire azimuth range. By using metallic pins, we implement a radially-dependent refraction index that, combined with a cylindrical reflector, results in a flat and symmetric system ideal for the excitation of reconfigurable antennas.
18:00 - 18:30 - Charge-Transfer Plasmon Polaritons at Graphene/α-RuCl3 Interfaces Invited oral [Show abstract]
  • D.N. Basov, Columbia University, USA
Nanoscale charge control is a key enabling technology in plasmonics, electronic band engineering, and topology of two-dimensional (2D) materials. By exploiting the large electron affinity of α-RuCl3, we are able to visualize and quantify massive charge transfer at graphene/α-RuCl3 interfaces through generation of charge-transfer plasmon polaritons (CPPs). We performed nano-imaging experiments on graphene/α-RuCl3 at both ambient and cryogenic temperatures and discovered robust plasmonic features in otherwise ungated and undoped structures. The CPP wavelength evaluated through several distinct imaging modalities offers a high-fidelity measure of the Fermi energy of the graphene layer: EF = 0.6 eV (n = 2.7  1013 cm–2). Our first-principles calculations link the plasmonic response to the work function difference between graphene and α-RuCl3 giving rise to CPPs. Our results provide a general strategy for generating nanometer-scale plasmonic interfaces without resorting to external contacts or chemical doping.
30 September 2020 / Start time: 9 h 0 min
09:00 - 10:00 - Plenary Session III
09:00 - Plenary session III

Session chairperson(s): Andrea Alu

09:00 - 10:00 - Recent advances in Mie-resonant metaphotonics Plenary [Show abstract]
  • Yuri Kivshar, Australian National University, Australia
Recently, we observe the emergence of a new field of all-dielectric resonant metaphotonics (also called “Mie-tronics”) aiming at the manipulation of strong optically-induced electric and magnetic Mie-type resonances in dielectric nanostructures with high refractive index. Unique advantages of dielectric resonant nanostructures over their metallic counterparts are low dissipative losses and the enhancement of both electric and magnetic fields that provide competitive alternatives for some problems in plasmonics including optical nanoantennas, biosensors, and metasurfaces. This talk will highlight some recent advances in all-dielectric Mie-resonant metaphotonics including bound the physics of bound states in the continuum, resonant nonlinear effects, and topological photonics.
10:00 - 10:30 - Coffee Break (Wednesday Morning)
10:30 - 12:30 - Oral Sessions (Wednesday Morning)
10:30 - Poster Session I: Acoustic and Mechanical metamaterial

Session chairperson(s): Angelica Viola Marini

1 - Deep-subwavelength Holey Acoustic Second-order Topological Insulators for Spoof Surface Wave Withdrawn [Show abstract]
  • Ying Cheng, Nanjing University, China
  • Dajian Wu, Nanjing Normal University, China
  • Desheng Ding, Southeast University, China
  • Xiaojun Liu, Nanjing University, China
Holey higher-order topological insulators are capable to sustain deeply confined corner states below 1/50 of the wavelength. Remarkable resilience of these surface confined acoustic states against defects and topologically-protected sound in three different frequency regimes are observed, which push forward exciting applications for robust acoustic imaging beyond the diffraction limit.
2 - Wave Propagation in Double-Negative Acoustic Metamaterial Multilayers Poster [Show abstract]
  • Takamichi Terao, Gifu university, Japan
The vibrational waves in a one-dimensional composite system containing double-negative acoustic metamaterials were studied. The transmission of sound waves of multilayer systems was numerically clarified. A method for calculating the transmission rate in these systems was also described.
3 - Flexural Waves on Elastic Thin Plates: Eaton Lens with Transmuted Singularities Poster [Show abstract]
  • Dongwoo Lee, Pohang University of Science and Technology, Korea (South)
  • Jeonghoon Park, Pohang University of Science and Technology, Korea (South)
  • Junsuk Rho, Pohang University of Science and Technology, Korea (South)
Eaton lens namely, omnidirectional retroreflector, enables light to reflect back to source-driven zone as an optical device used by transformation optics. However, in physical space, the requirement of a singularity accompanied by an extremely large refractive index struggles to make the realization. By making use of the transmuted index profile and considering flexural waves on a thin plate with hemispherical geometric curvature regarding thickness variations being scraped out, the inflexible demand of refractive index at the singularity point can be alleviated and also it gives rise to better efficiency compared to metamaterial scheme due to the curvature frame with smoothness in form factor.
4 - Resonance Scattering in Elastic Metamaterials Poster [Show abstract]
  • Omer Haq, University of Florida Department of Physics , USA
  • Sergei Shabanov, University of Florida Department of Mathematics, USA
Scattering of elastic waves off a single and double array of cylindrical scatters is considered for arbitrary polarizations. Analysis of the scattering problem is investigated via Lippmann Schwinger Integral Equation formalism; analytical expressions for the scattering amplitudes are used in order to analyze the resonances width. For the single array it is shown that the resonance width has a minimum which arises from elastic dipole interference that of which doesn't occur in similar photonic or acoustic structures. For the double array it is demonstrated that one can tune the width of the resonances to zero, forming a standing wave of mixed polarizations, a Bound State in the Continuum (BSC). These spectral states require more restrictive conditions on the parameters of the theory due to the polarization mixing and different dispersion between both polarizations.
Media link(s):

https://arxiv.org/abs/1906.00955

5 - Competing Interactions, and magnetization dynamics in Doped Rare-earth Manganites nanostructural system Withdrawn [Show abstract]
  • Wiqar Hussain Shah, International Islamic University, Islamabad, Pakistan
The Structural, magnetic and transport behavior of La1-xCaxMnO3+ (x=0.48, 0.50, 0.52 and 0.55 and =0.015) compositions close to charge ordering, was studied through XRD, resistivity, DC magnetization and AC susceptibility measurements. With time and thermal cycling (T<300 K) there is an irreversible transformation of the low-temperature phase from a partially ferromagnetic and metallic to one that is less ferromagnetic and highly resistive. For instance, an increase of resistivity can be observed by thermal cycling, where no effect is obtained for lower Ca concentration. The time changes in the magnetization are logarithmic in general and activation energies are consistent with those expected for electron transfer between Mn ions. The data suggest that oxygen non-stoichiometry results in mechanical strains in this two-phase system, leading to the development of irreversible metastable states, which relax towards the more stable charge-ordered and antiferromagnetic microdomains at the nano-meter size. This behavior is interpreted in terms of strains induced charge localization at the interface between FM/AFM domains in the antiferromagnetic matrix. Charge, orbital ordering and phase separation play a prominent role in the appearance of such properties, since they can be modified in a spectacular manner by external factor, making the different physical properties metastable. Here we describe two factors that deeply modify those properties, viz. the doping concentration and the thermal cycling. The metastable state is recovered by the high temperature annealing. We also measure the magnetic relaxation in the metastable state and also the revival of the metastable state (in a relaxed sample) due to high temperature (800 ) thermal treatment.
10:30 - Poster Session II:Analytical and numerical modelling of metamaterials and metasurfaces

Session chairperson(s): Stefano Vellucci

1 - A 3D-Printed Lightweight And Broadband Metamaterial Absorber By Copper-Based Semiconductor Filament Poster [Show abstract]
  • Zhen Yang, School of Mechanical Engineering, Xi'an Jiaotong University, China
  • Qingxuan Liang, School of Mechanical Engineering, Xi'an Jiaotong University, China
  • Yubing Duan, School of Mechanical Engineering, Xi'an Jiaotong University, China
  • Zhaohui Li, School of Mechanical Engineering, Xi'an Jiaotong University, China
  • Tianning Chen, School of Mechanical Engineering, Xi'an Jiaotong University, China
  • Dichen Li, School of Mechanical Engineering, Xi'an Jiaotong University, China
The PLA and 3D-printable copper-based semiconductor filament were selected to fabricate the substrate and resistive pattern, which had the characteristics of low density, and broadband absorbing. Foremost, such a complex perforated structure can be fully fabricated by Fused Deposition Modeling 3D printing.
2 - Electrodynamic Models of Composites and Metamaterials Based on the Method of Minimal Autonomous Blocks Poster [Show abstract]
  • Sergey Maly, Belarusian State University, Belarus
The technologies for the numerical analysis of the electrodynamic characteristics of systems consisting of composites, meta-surfaces, and metamaterials are considered. The developed methods, algorithms and programs allow to effectively model the interaction of electromagnetic radiation with structurally inhomogeneous materials with complex structural and material composition, including multiscale, nonlinearity, anisotropy.
3 - High Quality Factor Fabry-Perot Cavity: Double Dielectric Cylinder Array Metamaterial Poster [Show abstract]
  • Seokhyeon Hong, Department of Physics Chung-Ang University, Korea (South)
  • Youngsoo Kim, Department of Physics Chung-Ang University, Korea (South)
  • Eunso Shin, Department of Physics Chung-Ang University, Korea (South)
  • Young Jin Lee, Department of Physics Chung-Ang University, Korea (South)
  • Soon-Hong Kwon, Department of Physics Chung-Ang University, Korea (South)
<p> We propose a Fabry-Perot type optical cavity resonator based on a Mie resonances, consisting double dielectric cylinder array on low – index substrate. Single dielectric cylinder arrays have high reflectance at a particular period. Our Fabry-Perot cavity structure has a high transmittance and high quality factor of about 10^5.</p>
4 - Numerical Investigation of the Enhanced Propagation for Electromagnetic Non-destructive Testing by Metasurface-based Impedance Matching Poster [Show abstract]
  • Tong Hao, Tongji University, China
  • Wuan Zheng, Tongji University, China
In this paper, we present our numerical investigation results of the enhanced electromagnetic propagation when an antireflective metasurface superstrate is placed atop of the material under test for non-destructive testing applications. The simple metasurface design can effectively manipulate the transmission/reflection coefficients of the incident EM waves. The resultant enhanced propagation is numerically demonstrated for various MUT's properties, which provides a strong evidence for practical NDT applications.
5 - Toward Modeling of Complimentary Metamaterial Elements using Higher-order Moments for Metasurface Antenna Design Poster [Show abstract]
  • Insang Yoo, Duke University, United States
  • David Smith, Duke University, United States
We study the model of a complementary metamaterial element embedded in a waveguide wall as a collection of dipole and quadrupole moments. In the analytic model of a metasurface, the elements are often characterized as electric and magnetic point dipoles, with their higher-order moments ignored. In this study, we present the retrieval of the quadrupole moments of a metamaterial element etched into the top wall of a parallel-plate waveguide and demonstrate that considering the quadrupole moments of the element, in addition to its dipole moments, can improve the accuracy of the analytic model of a metamaterial element.
6 - Transformation Optics Devices with Metamaterials: Time-domain Models and Simulations No show [Show abstract]
  • Yunqing Huang, Xiang University , China
  • Jichun Li, University of Nevada Las Vegas, USA
  • Wei Yang, Xiangtan University, China
  • Bing He, Xiangtan University, China
Inspired by many interesting electromagnetic devices designed from transformation optics, here we illustrate how to derive the time-domain electromagnetic concentrator model. Then we present the theoretical analysis and time-domain finite element method for solving the model. Numerical results are presented to illustrate the concentrator's behavior.
7 - Gravitomagnetic Dipole Moment of Gravitational Unit Cells Poster [Show abstract]
  • Thomas Weldon, Univ. of N. Carolina at Charlotte, USA
  • Christopher Daniel, Univ. of N. Carolina at Charlotte, USA
  • Kathryn Smith, Univ. of N. Carolina at Charlotte, USA
We propose that gravitational meta-atoms (or unit cells) with gravitomagnetic moments could exhibit gravitomagnetic permeability, analogous to the magnetic permeability of materials comprised of atoms with magnetic moments. In this paper, GEM field approximations to general relativity are used to derive the gravitomagnetic dipole moment of gravitational systems.
10:30 - Poster Session III: RF and Thz Metasurface and Metamaterials

Session chairperson(s): Alessio Monti

1 - Excitation of the Light Line Mode with Metamaterials Composed of Parallel Conductors Based On Equivalent-Circuit Model Including Retarded Electromagnetic Coupling Poster [Show abstract]
  • Daisuke Akimaru, Kyoto University, Department of Electrical Engineering, Japan
  • Takashi Hisakado, Kyoto University, Department of Electrical Engineering, Japan
  • Mahfuzul Islam, Kyoto University, Department of Electrical Engineering, Japan
  • Osami Wada, Kyoto University, Department of Electrical Engineering, Japan
We clarify the mechanism for the phenomenon of parallel conductors at the light line. By analyzing them with a circuit model including retardation, the singularity at the light line is clarified. Using this singularity, we can excite the light line mode specifically and form a beam with a sharp directivity.
2 - Surface Modification of Ag Nanocrystals to Design High Performance Electromagnetic Interference Shielding Properties Withdrawn [Show abstract]
  • Ji-Hyuk Choi, Korea Institute of Geoscience and Mineral Resources, Korea (South)
  • Soong Ju Oh, Korea University, Republic of Korea
Electromagnetic interference (EMI) pollution world and seriously affects the operation safety of various electronic devices electronic systems and telecommunications. The undesirable heat emissions and electromagnetic radiation result in degrade the performance of electronic components as well as its harmful effects on human health. Therefore there is a critical need for developing effective and practical EMI shielding materials with a low-cost and scalable solution fabrication process. Recently colloidal nanocrystal (NC) thin films have attracted great attention in a wide variety of applications since the overall properties of the NC thin films strongly depend on the surface chemistry of NC. Herein, we introduce NC-based EMI shielding materials through ligand-exchanged, conductive silver (Ag) NCs. The ligand exchange process with optimum condition enables the stabilization of NC in the form of colloidal, allowing their bottom-up multi-layered films. Ag NC films treated with short and compact inorganic ligands successfully provide highly conductive thin films with markedly different EMI shielding properties. By controlling nanocracks in Ag NC film, we monitored the structural states and dramatically change EMI shielding properties. Resultant Ag NC films showed excellent EMI shielding effectiveness greater than 40 dB in a frequency range from 8 MHz to 12 GHz. This strategy provides new opportunities to construct scalable and high-performance EMI shielding materials for advanced flexible applications.
3 - Equivalent-circuit-based Stability Analysis of non-Foster SCS Negative Capacitor Poster [Show abstract]
  • Ante Brizic, University of Zagreb, Faculty of Electrical engineering and computing, Croatia
  • Silvio Hrabar, University of Zagreb, Faculty of Electrical engineering and computing, Croatia
Equivalent circuit of a non-Foster negative capacitor, based on an SCS voltage inversion negative converter with one-pole and two-pole amplifier model, has been developed. The circuit was loaded with an external RC network of series or parallel type, and the stability of the whole system is investigated. It was found that there is always a trade-off between operating bandwidth and the range of external capacities and resistances that assure stable operation.
4 - Advanced Manufacturing Techniques for Structurally Integrated Metasurfaces Poster [Show abstract]
  • Kelvin Nicholson, DST, Australia
  • Thomas Baum, DST, Australia
  • Jian Yu, ARL, US
Two easily scalable manufacturing techniques to realize conformal metasurface antennas embedded in a structural laminate are presented. Given the finite size of the manufactured samples, a numerically simulated ‘reference’ wave was used in the design process to further improve the electromagnetic performance of these antennas.
5 - Electrodynamic Analysis of Combined Frequency Selective Structures from Wire Gratings Poster [Show abstract]
  • Sergey Maly, BSU, Belarus
  • Hanna Arlova, BSU, Belarus
Interaction of a plane electromagnetic wave with structures comprising two co-located in one plane periodic gratings from infinite and finite on length conductors was investigated. It is established that combining grids into one structure leads to its full transparency at fixed frequencies. Variation in the size of gaps between the ends of conductors leads to changes in frequency corresponding to the maximum transmission coefficient. This effect can be used to create frequency selective structures with a tunable transmission coefficient.
6 - Millimeter-Wave Meta Cells Loaded Coplanar Transmission Line for Component Applications Poster [Show abstract]
  • Hardly Joseph Christopher, Department of Information Engineering, Università Politecnica delle Marche, Ancona, Italy, Italy
  • Davide Mencarelli, Department of Information Engineering, Università Politecnica delle Marche, Ancona, Italy, Italy
  • Luca Pierantoni, Department of Information Engineering, Università Politecnica delle Marche, Ancona, Italy, Italy
In this work, a planar transmission line loaded with square shaped split ring resonator (SRR) metamaterials works around 150 GHz is modeled and validated by means of full-wave electromagnetic simulations. The transmission characteristics of such a transmission line is reported. The SRR loaded coplanar waveguide (CPW) structure exhibits stop band characteristics in response to the resonance of the inductively coupled SRR rings excited by the magnetic fluxes through the rings. A parametric analysis of the rings and arrays of SRRs carried out to predict the behavior of the meta cells loaded transmission line. Since these metamaterials are much smaller than the feeding signal wavelength, these metamaterials loaded transmission lines are potentially useful to optimize size and quality factor of millimeter-wave circuit components and radiating elements.
10:30 - Poster Session IV:Plasmonics Metamaterials

Session chairperson(s): Viktoriia Rutckaia

1 - Comparative Study of Monocrystalline and Polycrystalline Plasmonic Antennas Fabricated by Electron and Ion Beam Lithography Poster [Show abstract]
  • Vlastimil Křápek, Brno University of Technology, Czech Republic
  • Michal Horák, Brno University of Technology, Czech Republic
  • Lukáš Kejík, Brno University of Technology, Czech Republic
  • Kristýna Bukvišová, Brno University of Technology, Czech Republic
  • Vojtěch Švarc, Brno University of Technology, Czech Republic
  • Tomáš Šikola, Brno University of Technology, Czech Republic
We compare structural, chemical, and optical properties of monocrystalline and polycrystalline plasmonic antennas fabricated by electron and ion beam lithography. The antennas fabricated by electron lithography are superior to those fabricated by ion beam lithography. No significant effect of the crystallinity is observed.
2 - Fabrication and Optical Properties of Plasmonic Nanocomposite Structures. Poster [Show abstract]
  • Yaroslava Andreeva, ITMO University, Russia
  • Pavel Varlamov, ITMO University, Russia
  • Francis Vocanson, University of Lyon, Laboratoire Hubert Curien, UMR CNRS 5516/UJM, France
  • Nathalie Destouches, University of Lyon, Laboratoire Hubert Curien, UMR CNRS 5516/UJM, France
  • Tatiana Itina, University of Lyon, Laboratoire Hubert Curien, UMR CNRS 5516/UJM, France
In this work, we demonstrate a single-step laser-assisted fabrication of thin plasmonic nanocomposite thin films. The common processes taking place in Ag:Au:TiO2 thin nanocomposite films under UV laser irradiation are discussed. We describe the main nanostructure formation mechanisms, as well as their effect on the optical properties of the films. The obtained results pave the way for the implementation of such materials in modern photonics and optoelectronics devices, photocatalytic systems, sensing, and SERS due to their unique and well-controlled optical properties.
3 - Transition to Strong Coupling Regime for Quantum Emitters Coupled to a Plasmonic Resonator Withdrawn [Show abstract]
  • Tigran Shahbazyan, Jackson State University, USA
We present a model for exciton-plasmon coupling based on energy exchange between emitters and localized surface plasmons in metal-dielectric structures. Plasmonic correlations between emitters give rise to a collective state exchanging its energy with a resonant plasmon mode. By accurately defining the plasmon mode volume, we relate the QE-plasmon coupling to collective energy transfer rate. For QEs distributed in extended region enclosing a plasmonic structure, the ensemble QE-plasmon coupling saturates to a universal value independent of system size and shape.
4 - Surface Plasmon Drag at Metasurfaces with Periodic Arch Structure Poster [Show abstract]
  • Yuto Masunaka, Tohoku University, Japan
  • Teruya Ishihara, Tohoku University, Japan
Photovoltage excited by circular polarized light is demonstrated on a periodic arch structure engraved in a Au film. In order to determine the character of the voltage it is essential to know the sense of circular polarization.
5 - Design and Characterization of an Integrated Metasurface-Based Plasmonic Axicon Lens on SOI No show [Show abstract]
  • Yulong Fan, University of Paris Sud, France
  • Benoit Cluzel, University of Bourgogne, France
  • Marlene Petit, University of Bourgogne, France
  • Xavier Le Roux, University of Paris Sud, France
  • Anatole Lupu, University of Paris Sud, France
  • Andre de Lustrac, University of Paris Sud, France
in this paper we demonstrate experimentally by near-field imaging the propagation of a diffraction-free Bessel-type beam in a guided wave configuration generated by means of a metasurface-based axicon lens integrated on a silicon waveguide. Full wave simulations are in excellent agreement with near field measurements.
6 - Design of High-Transmission Plasmonic Wavelength and Polarization Filters for Infrared Photodetectors Poster [Show abstract]
  • Tobias Wenger, Jet Propulsion Laboratory, California Institute of Technology, USA
  • Alexander Soibel, Jet Propulsion Laboratory, California Institute of Technology, USA
We discuss the design and fabrication of plasmonic filters that can be integrated with infrared photodetectors to create highly compact instruments for space applications. The filters are designed for the wavelengths 3-5 micrometers and simultaneously perform wavelength and polarization filtering.
7 - Effective Medium Approach for Investigation of Optical Properties of Nanocomposites with Plasmonic Nanoparticles Poster [Show abstract]
  • Pavel Varlamov, ITMO University, Russia
  • Maxim Sergeev, ITMO University, Russia
  • Francis Vocanson, University of Lyon, France
  • Tatiana Itina , University of Lyon, France
<p> We present an approach based on effective medium theory in the Burgerman-Bergman approximation for modeling of optical properties of nanocomposites based on TiO2 and SiO2 films with Ag nanoparticles. The importance of volume fraction of metal phase for spectral characteristics of such nanocomposite is demonstrated and confirmed. The increase of this parameter leads to the redshift of the spectral peak and an increase of the reflection amplitude. The numerical calculations demonstrate a good agreement with the experimental data for laser-obtained TiO2- and SiO2-based nanocomposite films with Ag nanoparticles.</p>
10:30 - Poster Session V:Optical Metamaterials

Session chairperson(s): Mirko Barbuto

1 - Efficient Second Harmonic Generation from Double Resonant Au Metasurfaces Poster [Show abstract]
  • Yusuf Habibullah, Tohoku University, Japan
  • T. Ishihara, Tohoku University, Japan
<p> Plasmonic metamaterial are characterized with plasmonic modes, of which field can be resonantly enhanced at particular wavelengths. This gives room to enhance nonlinear process such as second harmonic generation (SHG). Here we report SHG spectroscopy for double resonant (DR) plasmonic single nanoantenna array with resonances for cross polarized excitation at pump and emission wavelength. In addition, using finite element method (FEM), we numerically demonstrate how the type of mode generated at each resonant wavelength determines the efficiency of the generated SHG signal at double resonance. The experimental data can be explained in terms of the SH intensity wavelength dependence of double resonant and single resonant plasmonic metasurfaces. Our finding paves a way to design and fabricate double resonant nonlinear medium with single nanoantenna constituent for efficient nonlinear response.</p>
2 - Tunable Inverse Faraday effect in the Photonic Crystal Nanostructures with the Magnetic Layer of Gradient Thickness Poster [Show abstract]
  • Olga Borovkova, Russian Quantum center, Russia
  • Mikhail A. Kozhaev, Russian Quantum center, Russia
  • Andrey N. Kalish, Russian Quantum center, Russia
  • Vladimir I. Belotelov, Russian Quantum center, Russia
The PC nanostructures with magnetic layer of gradient thickness are proposed. Two designs of magnetic PC nanostructures are discussed. The smooth magnetic layer provides gradual tuning of the IFE, and the perforated magnetic layer allows spatially localized emergence of the IFE in the spots of several microns.
3 - Two-Dimensional Metamaterials for Enhancement of Photon Emission and Absorption Withdrawn [Show abstract]
  • Dao Hua Zhang, Nanyang Technological University, Singapore
We study electromagnetic field enhancement of plasmonic resonator array and the applications for enhancing emission and enhanced photodetection. By varying the dimension of the star-shape resonators, emission enhancements in the semiconductor quantum dots can be monitored and an enhancement factor of ~6 times has been demonstrated. By adjusting the resonance mode of the resonator array integrated with a mid-infrared semiconductor photodiode, the room temperate specific detectivity of greater than 1010 Jones can be achieved.
4 - Graphene Assisted Tunable Narrowband Metamaterial Absorber for Infrared Wavelength Withdrawn [Show abstract]
  • Vishal Sorathiya, Marwadi University, India
  • Zen Sbeah, Marwadi University, India
Put your abstract hWe proposed the narrow band graphene metamaterial-based infrared tunable absorber. Proposed absorber structure is numerically investigated over the 1.5μm to 1.6μm wavelength range. The proposed absorber structure is tunable for the wide range of the chemical potential that can be controlled with external biasing. It offers the perfect absorption in the multiple narrowband regions. The absorber work as metamaterial because it is observed the negative refractive index response at resonating frequency.ere
5 - Efficient Mie Resonance of Metal-masked Titanium Dioxide Nanopillars Poster [Show abstract]
  • Xiao Shang, Chinese Academy of Sciences, Institute of Microelectronics, China
  • Lina Shi, Chinese Academy of Sciences, Institute of Microelectronics, China
  • Jiebin Niu, Chinese Academy of Sciences, Institute of Microelectronics, China
  • Changqing Xie, Chinese Academy of Sciences, Institute of Microelectronics, China
We propose a simple design approach based on metal-masked titanium dioxide nanopillars, which can realize strong Mie resonance in metasurfaces and enables light confinement within itself over the range of visible wavelengths. By selecting the appropriate period and diameter of individual titanium dioxide nanopillars, the coincidence of resonance peak positions derived from excited electric and magnetic dipoles can be achived.
10:30 - SPC Final (Reserved to Finalists and Committee Members)
12:30 - 14:00 - Lunch Break (Wednesday)
14:00 - 15:30 - Oral Sessions (Wednesday Afternoon 1)
14:00 - Special session: Physical Review Symposium II

Session chairperson(s): Andrea Alu

14:00 - 14:30 - Asymmetric Coding Metasurfaces for the Controllable Projection of Acoustic Images Invited oral [Show abstract]
  • Ying Cheng, Nanjing University, China
  • Dajian Wu, Nanjing Normal University, China
  • Desheng Ding, Southeast University, China
  • Xiaojun Liu, Nanjing University, China
Acoustic coding metasurface consisting of identical asymmetric acoustic unit (AAU) is proposed. The AAU is tunable in transmission coefficient and reflection phase asymmetry, functioning as coding elements 0/1 when patterned in regular/inverse form. We demonstrate efficient projection of complex acoustic images and achieve controllable encryption and decryption of acoustic images.
14:30 - 15:00 - Valley Acoustoelectric Effect in Two-Dimensional Materials Invited oral [Show abstract]
  • Alexander Kalameitsev, Rzhanov Institute of Semiconductor Physics SB RAS, 630090 Novosibirsk, Russia, Russia
  • Vadim Kovalev, Novosibirsk State Technical University, Novosibirsk, 630072 Russia, Russia
  • Ivan Savenko, Center for Theoretical Physics of Complex Systems, Institute for Basic Science (IBS), Daejeon 34126, Korea, Korea (South)
We will report on the Valley Acoustoelectric Effect (VAE), which represents an extension of the Acoustoelectric Effect and arises in two-dimensional metamaterials, like transition metal dichalcogenide (TMD) monolayers. This effect consists in the emergence of a drag Hall electric and a spin currents due to the propagation of surface acoustic waves along the sample, exposed to external polarized light.
15:00 - 15:30 - From Local Density of Photonic States to Green’s Tensor Measurements in Microwaves Invited oral [Show abstract]
  • Kaizad Rustomji, Aix-Marseille University, France
  • Marc Dubois, Aix-Marseille University, France
  • Pierre Jomin, Aix-Marseille University, France
  • Jérôme Wenger, Aix-Marseille University, France
  • C. Martijn De Sterke, University of Sydney, Australia
  • Redha Abdeddaim, Aix-Marseille University, France
  • Stefan Enoch, Aix-Marseille University, France
We show experimentally and numerically how antenna impedance measurements provide knowledge of the local photon density of states, as well as of Förster resonant energy transfer, the non-radiative energy exchange between two dipoles. We further generalize this to the full complex electromagnetic Green tensor, which completely characterizes an electromagnetic environment and its effect on cooperative phenomena.
14:00 - Mechanical and elastic metamaterials II

Session chairperson(s): Seunghwi Kim

14:00 - 14:30 - The odd free surface flows of a colloidal chiral fluid Invited oral [Show abstract]
  • Vishal Soni, University of Chicago, USA
  • Ephraim Bililign, University of Chicago, USA
  • Sofia Magkiriadou, University of Chicago, USA
  • Stefano Sacanna, New York University, USA
  • Michael Shelley, New York University, USA
  • William Irvine, University of Chicago, USA
In simple fluids, such as water, invariance under parity and time-reversal symmetry imposes that the rotation of constituent ‘atoms’ is determined by the flow and that viscous stresses damp motion. Mechanically excited hydrodynamic surface waves propagate isotropically. Activation of the rotational degrees of freedom of a fluid by spinning its atomic building blocks breaks these constraints and has thus been the subject of fundamental theoretical interest across classical and quantum fluids. I will discuss the creation of a cohesive two-dimensional chiral liquid consisting of millions of spinning colloidal magnets and study its flows. We find a new mechanism for chiral surface wave propagation which we dub viscous ‘edge-pumping’. We further find the presence of chiral instabilities with no counterpart in conventional fluids. Spectral measurements of the chiral surface dynamics suggest the presence of Hall viscosity, an experimentally elusive property of chiral fluids with analogs in plasmas and quantum, fluids. Precise measurements and comparison with theory demonstrate excellent agreement with a minimal chiral hydrodynamic model, paving the way for the exploration of chiral hydrodynamics in experiment.
14:30 - 14:45 - Feedback-based Topological Mechanical Metamaterials Oral [Show abstract]
  • Lea Sirota, Raymond and Beverly Sackler School of Physics and Astronomy, Tel Aviv University, Israel
  • Yoav Lahini, Raymond and Beverly Sackler School of Physics and Astronomy, Tel Aviv University, Israel
  • Roni Ilan, Raymond and Beverly Sackler School of Physics and Astronomy, Tel Aviv University, Israel
  • Yair Shokef, School of Mechanical Engineering and Sackler Center for Computational Molecular and Materials Science, Tel Aviv University, Israel
We present a method to design autonomous active metamaterials that can create arbitrary physical interactions on a single, reprogrammable platform, including non-local, non-linear, time-dependent or non-Newtonian couplings. The underlying principle includes application of external forces to a regular mechanical lattice, and processing them in real-time through closed-loop controllers that are pre-programmed to create desired couplings between the metamaterial sites. As an example, we demonstrate that a lattice constrained to out-of-plane vibration can be programmed to exhibit an analogy either of the quantum spin Hall effect, or the quantum Hall effect, thereby enabling a versatile unconventional guiding of mechanical waves.
14:45 - 15:00 - Tunable Frequency Band Structure In Photo-responsive Elastic Metamaterials Oral [Show abstract]
  • Antonio Gliozzi, Politecnico di Torino, Italy
An important issue in the field of elastic metamaterials is that their dynamic properties, such as the band gap frequencies, are typically fixed once the structure has been designed and fabricated. To overcome this limitation, many efforts have been made to conceive materials with adaptive elastic properties based on piezoelectric materials, temperature and magneto-based techniques, actuated polymers via electromagnetic waves, as well as the application of an external mechanical load. In the present research we present an alternative approach based on light-responsive polymers. We show the possibility to reversibly change the material parameters in specific regions of the unit cells of these structures through external light stimuli, leading to the tunability of their transmission spectrum.
15:00 - 15:15 - Tunable Elastic Wave Bandgap and Local Resonances in Single-phase Metamaterial with Applied Deformation Oral [Show abstract]
  • NITISH KUMAR, Indian Institute of Technology Roorkee, India
  • SILADITYA PAL, Indian Institute of Technology Roorkee, India
Metamaterial with bandgap tunability is an emerging area in manipulating elastic wave transmission characteristics for next generation phononic devices. Although several attempts are made employing multi-fields such as magnetic, electric and thermal etc., mechanical deformation based tunable bandgap is a major interest. However, achieving tunability in terms of broadening or terminating the bandgap in single-phase locally resonant acoustic metamaterial (LRAM) remains as challenging tasks. In this work, we explore the bandgap of a single-phase star shaped structure with applied deformation. Initially, a quasi-static analysis of unit cell has been performed to find the static displacement field under prescribed deformation. Further, a linearized elastodynamics is adopted for wave analysis of the predeformed periodic unit cell, and we apply Bloch-Floquet boundary condition. Subsequently, utilizing finite element based framework, an eigenvalue problem is formulated. Accordingly, dispersion responses are predicted and bandgaps are extracted for specified external mechanical deformation. In particular, the development of bandgap under equibiaxial tensile deformation is addressed, and underlying local resonances (dipole, quadrupole and monopole) are explained through vibration mode shapes.
15:15 - 15:30 - Chiral Elastic Meta-beam for Enhancing Flexural Wave Attenuation Oral [Show abstract]
  • Jeonghoon Park, Pohang University of Science and Technology (POSTECH), Korea (South)
A new chiral elastic meta-beam is proposed to attenuate the propagation of flexural waves. A chiral and achiral meta-beam is designed and their band structures are numerically calculated. Transmission loss is considered for verification. This approach will pave the way for the design of chiral meta-structures for attenuation of vibrations.
14:00 - Photonic Crystal and EBG structure I

Session chairperson(s): Mohammad-Ali Miri

14:00 - 14:15 - Temporal Photonic (Time-) Crystal with a Square Profile of Both Permittivity and Permeability No show [Show abstract]
  • José Gabriel Gaxiola-Luna, Institute National of Astrophysics, Optics and Electronics, Mexico
  • Peter Halevi, Institute National of Astrophysics, Optics and Electronics, Mexico
We study a temporal photonic crystal with square profile of permittivity and permeability. The continuity of the D(t) and B(t) fields across the time discontinuities facilitates the Konig-Penney methodology, leading to an analytic photonic band structure (PBS). It is periodic in frequency and exhibits k-bands separated by k-gaps, but for equal modulations the PBS is composed of straight lines without k-gaps. The field D(t) displays the Bloch-Floquet behavior. We also study the Zak phase associated with the PBS.
14:15 - 14:30 - On-chip Integration and Degree of Freedom Exploration in Valley Photonic Systems Oral [Show abstract]
  • Guo-Jing Tang, Sun Yat-sen University, China
  • Xin-Tao He, Sun Yat-sen University, China
  • Xiao-Dong Chen, Sun Yat-sen University, China
  • Jian-Wen Dong, Sun Yat-sen University, China
In this talk, we show the topological transport in a SOI valley photonic crystal slab. The topological robust transport at telecommunication wavelength is observed and topological photonic routing is achieved. We also proposed valley photonic systems combining layer or frequency degree of freedoms with valley degree freedom. These valley photonic systems enrich the topological nontrivial phases and offers more methods on light manipulation.
14:30 - 14:45 - Theoretical and Experimental Investigation of the Emergence of Surface States on Photonic Crystals as Hybrid Dielectric Metasurface Bound States of the Termination Layer Oral [Show abstract]
  • Anna Tasolamprou, Institute of Electronic Structure and Laser, FORTH, Greece
  • Lei Zhang, Iowa State University, USA
  • Eleftherios Economou, Institute of Electronic Structure and Laser, FORTH, Greece
  • Costas Soukoulis, Iowa State University, USA
  • Thomas Koschny, Iowa State University, USA
We provide a novel perspective on surfaces states arising from the corrugated termination of a photonic crystal that would otherwise not support any surface states. Through theoretical and experimental investigations, we associate the photonic crystals surface states with metasurface bound states which selectively interact and hybridize with the band structure of the bulk photonic crystal.
14:45 - 15:00 - A Generalized Modal Analysis for the Optimization of Multiconductor Transmission-Line-Based Electromagnetic Bandgap Structures Oral [Show abstract]
  • Stuart Barth, Independent Researcher, Canada
Traditionally, the analysis of electromagnetic bandgap structures designed with multiconductor transmission-line metamaterial techniques has been limited to geometrical changes in the host transmission lines, or variation in the loading components. This work investigates adjusting the modal properties of the host transmission lines, thereby forming a set of universal design considerations which may be applied regardless of the layout of the physical structure.
14:00 - Metamaterial and metasurface antennas II

Session chairperson(s): Younes Ra'di

14:00 - 14:30 - Broadening Antenna Bandwidth by Time-Modulation Invited oral [Show abstract]
  • Yakir Hadad, Tel-Aviv University, Israel
  • Amir Shlivinski, Ben-Gurion University, Israel
The Chu bound imposes constraints on the radiation characteristics of small antennas, namely, directivity and directivity-bandwidth product. We consider effective time modulation of a small antenna structure as a means to broaden these radiation characteristics, beyond what expected for passive, linear, time-invariant antenna systems.
14:30 - 14:45 - Exploiting Vortex Modes in the Design of Patch Antennas for Pattern Diversity and MIMO Systems Oral [Show abstract]
  • Mirko Barbuto, Niccolò Cusano University, Italy
  • Andrea Alù, City University of New York, USA
  • Filiberto Bilotti, ROMA TRE University, Italy
  • Alessandro Toscano, ROMA TRE University, Italy
In this contribution, we expand the possibility offered by structured fields at microwave frequencies by exploiting phase singularity points of vortex modes for designing a single radiating structure exhibiting orthogonal radiation patterns pointing in different directions. This kind of structure, being able to radiate two orthogonal polarizations with low-coupling levels, can be exploited in compact multi-antenna systems for antenna diversity or MIMO applications.
14:45 - 15:00 - Non-Foster Self-oscillating Single-loop Antenna Oral [Show abstract]
  • Silvio Hrabar, University of Zagreb, Croatia
  • Dmitry Kholodnyak, LETI, Russia
  • Bair Buiantuev, LETI, Russia
  • Dominik Dobrijevic, University of Zagreb, Croatia
  • Marin Jakovcev, University of Zagreb, Croatia
  • Matko Martinic, University of Zagreb, Croatia
  • Ante Zeljko, University of Zagreb, Croatia
  • Igor Krois, University of Zagreb, Croatia
<p> A recently proposed concept of a self-oscillating non-Foster antenna array is modified for the case of a single loop. The idea was tested by simulations of a model of small loop integrated with a Linvill floating INIC and operating in 50 MHz RF band. Obtained results revealed efficient self-oscillations with a 1:2 tuning bandwidth and the suppression of harmonics better than 20 dB. This antenna might find application in future active metasurfaces.</p>
15:00 - 15:15 - Dipole Antennas with Time-Varying Body and Shape Oral [Show abstract]
  • Mohamed Hesham Mostafa, Aalto University, Finland
  • Grigorii Ptitcyn, Aalto University, Finland
  • Sergei Tretyakov , Aalto University, Finland
In this talk we introduce a concept of antenna body modulation. We show approximated theoretical formulas for effective resistance and reactance at the carrying frequency and discuss how antenna body modulation can affect them. Finally, we show how radiation resistance can be decreased keeping the reactance unchanged in the limit of small modulations.
15:15 - 15:30 - Antenna Applications of Frequency- And Time-Domain Selective Devices Oral [Show abstract]
  • Stefano Vellucci, ROMA TRE University, ELEDIA Research Center , Italy
  • Mirko Barbuto, Niccolò Cusano University, Italy
  • Alessio Monti, Niccolò Cusano University, Italy
  • Alessandro Toscano, ROMA TRE University, Italy
  • Filiberto Bilotti, ROMA TRE University, Italy
Recently, circuit loaded metasurfaces exhibiting different responses depending on the waveform of the incoming waves have been proposed. Here, we extend this approach presenting two different antenna applications. As a first example, we report an open-ended waveguide antenna capped with a band-pass filtering iris loaded with a lumped element circuit. Thanks to its peculiar frequency- and time-domain selectivity response the antenna exhibits different radiating patterns depending on the waveform of the transmitted/received signal. The same circuit is also exploited to design a mantle cloak able to hide an antenna to a pulsed radar system while keeping its radiation characteristics unaffected for a continuous-wave signal.
14:00 - Fabrication and experimental characterization

Session chairperson(s): You Zhou

14:00 - 14:15 - Biological Foundries for the Manufacture of THz and Optical Metamaterials Oral [Show abstract]
  • Simon Butler, University of Huddersfield, United Kingdom
  • Rebecca Seviour, University of Huddersfield, United Kingdom
  • Alistair Elfick, University of Huddersfield, United Kingdom
Top down nanofabrication approaches lack the fidelity coupled with throughput to create the sub 100 nanometer unit cell, sub 10 nanometer feature size, meta atoms required to create metamaterials operating within the optical regime. We present a novel fabrication methodology enabling the fabrication of highly purified meta atoms with yields sufficient to create effective materials.
14:15 - 14:30 - Chalcogenide Phase-Gradient Metasurfaces as a New Route Towards Mass-Production Oral [Show abstract]
  • Elena Mikheeva, Institute Fresnel / Multiwave Imaging, France
  • Julien Lumeau, Institute Fresnel, France
  • Guillaume Baffou, Institute Fresnel, France
  • Igor Ozerov, CINAM, France
  • Frédéric Bedu, CINAM, France
  • Redha Abdeddaim, Institute Fresnel, France
  • Stefan Enoch, Institute Fresnel, France
With the rapid progress in the field of metasurfaces and their use in miniature integrated devices arise the quest for cheap mass-production of efficient metasurfaces. We suggest a novel way to design and fabricate all-dielectric Huygens metasurfaces using photo-annealing of As2S3 chalcogenide glass. Our method has potential advantages for the low-cost production of metasurfaces-based compact devices
14:30 - 14:45 - 2.5D Metastructures; Design, Optimization, and Experimental Demonstration Oral [Show abstract]
  • Mahdad Mansouree, University of Massachusetts Amherst, USA
  • Hyounghan Kwon, California Institute of Technology, USA
  • Ehsan Arbabi, California Institute of Technology, USA
  • Andrew McClung, University of Massachusetts Amherst, USA
  • Andrei Faraon, California Institute of Technology, USA
  • Amir Arbabi, University of Massachusetts Amherst, USA
We present the design, fabrication, and characterization of multifunctional 2.5D metastructures using adjoint optimization. Our technique considers complex interactions among meta-atoms and offers significantly improved performance compared to conventional unit-cellbased techniques.
14:45 - 15:00 - Electron-Beam Lithography Fabrication Process Development For A Mid-IR Plasmonic Metasurface With Fine Features Oral [Show abstract]
  • Mitchell Semple, University of Alberta, Canada
  • Ashwin Iyer, University of Alberta, Canada
We show the development of a 100 keV electron-beam lithography liftoff fabrication process for a plasmonic metasurface designed to resonate at 15 µm. Such a metasurface may prove useful in enhancing mid-IR absorption spectroscopy, e.g. for CO2 detection. Helium ion beam microscopy and Fourier transform infrared spectroscopy show evidence of the expected resonance, but which has been shifted outside of the measurable range due to variations in exposure and thickness.
15:00 - 15:15 - Measurement of an Infrared Plasmonic Out-of-Plane 3D Thin-Film Meta-surface Beamsteerer Oral [Show abstract]
  • Carlos Diaz, Air Force Institute of Technology, USA
  • Michael Marciniak, Air Force Institute of Technology, USA
  • Matthew Miller, Air Force Institute of Technology, USA
  • Augustine Urbas, Air Force Research Laboratory, USA
  • Bruce Burckel, Sandia National Laboratory, USA
  • Eric Whiting, Pennsylvania State University, USA
  • Sawyer Campbell, Pennsylvania State University, USA
  • Douglas Werner, Pennsylvania State University, USA
Bidirectional Transmittance Distribution Function (BTDF) measurements of an out-of-plane (OOP) metasurface beamsteerer were carried out at 6 μm for four different polarization states. These are compared to ideal models of the metasurface beamsteerer to compare and contrast behaviors in ideal and measured results.
15:15 - 15:30 - Three-Dimensional Meta-films – A Discovery Platform for Structured Electromagnetic Materials Oral [Show abstract]
  • D. Bruce Burckel, Sandia National Laboratories, USA
  • Katherine Musick, Sandia National Laboratories, USA
  • Paul Resnick, Sandia National Laboratories, USA
  • Michael Sinclair, Sandia National Laboratories, USA
  • Michael Goldflam, Sandia National Laboratories, USA
A wall-first variant of membrane projection lithography (MPL) is introduced which yields three-dimensional meta-films; mm-scale structures with micron-scale periodicity and 3D nm-scale unit cell structure. These meta-films combine aspects of photonic crystals, metamaterials and plasmonic nano antennas in their infrared scattering behavior. We present the fabrication approach, and modeling/IR characterization results.
15:30 - 16:00 - Coffee Break (Wednesday Afternoon)
16:00 - 17:30 - Oral Sessions (Wednesday Afternoon 2)
16:00 - Optical metamaterials II

Session chairperson(s): Alex Krasnok

16:00 - 16:15 - Parallel Optical Spatial Signal Processing Based on 2×2 MIMO Computational Metasurface Oral [Show abstract]
  • Amirhossein Babaee, Iran University of Science and Technology, Iran
  • Ali Momeni, Iran University of Science and Technology, Iran
  • Mohammad Moein Moeini, Wayne State University, USA
  • Romain Fleury, Swiss Federal Institute of Technology in Lausanne (EPFL), Switzerland
  • Ali Abdolali, Iran University of Science and Technology, Iran
We introduce a novel concept of Multi-Input Multi-Output (MIMO) metasurface processor with asymmetric Optical Transfer Function (OTF) which can perform spatial firstorder derivation on two orthogonal distinct input signals for both TM and TE polarizations. Two distinct input signals, regardless of their polarization, simultaneously illuminate the metasurface computer and the resulting differentiated signals are separated from each other via appropriate Spatial Low Pass Filters (SLPF). Our simulations confirm the claim of a 2×2 MIMO optical differentiator processor. The proposed metasurface computer is away from the restrictions such as lack of computing speed, large size of bulky or two additional sub-blocks, supporting only a single input, and constant polarization mode. Our proposed scheme pave the way for real-time massive parallel signal processing by single metasurface.
16:15 - 16:30 - Discrete-Space Metamaterials for Optical Signal Processing Oral [Show abstract]
  • Mohammad Moein Moeini, Wayne State University, USA
  • Dimitrios Sounas, Wayne State University, USA
Optical signal processing (OSP) has recently received renewed interest as digital computers are approaching the processing limits dictated by Moore’s law. Here, inspired by digital filters, we propose a new type of OSP metamaterials based on discretization of optical waves in space and subsequent implementation of the desired mathematical operation on the discretized wave. A first order differentiator (subtractor) metasurface in transmission mode is designed as a proof of concept. Compared to other techniques, our approach is characterized by modularity, adaptivity to different forms of operations, broader bandwidth and lower loss.
16:30 - 16:45 - Tune the Polarization States of Light via Metastructures-- From Passive to Active Withdrawn [Show abstract]
  • Ruwen Peng, Nanjing University, China
  • Mu Wang, Nanjing University, China
We present our recent work on tuning the polarization states (PSs) of light passively or actively with both 2D/3D metastructures. It is shown that the PSs are manipulated by a time-retardation metasurface, dispersion-free metastructures and phase-changed hybrid materials. The investigations provide some guidelines to control the PSs at subwavelength scale.
16:45 - 17:00 - Contracting 3D Optics into a Surface: Multiresonant Achromatic Gradient Metasurfaces in Transmission and Reflection Oral [Show abstract]
  • Odysseas Tsilipakos, Foundation for Research and Technology Hellas, Greece
  • Maria Kafesaki, Foundation for Research and Technology Hellas, Greece
  • Eleftherios Economou, Foundation for Research and Technology Hellas, Greece
  • Costas Soukoulis, Ames Laboratory and Iowa State University, USA
  • Thomas Koschny, Ames Laboratory and Iowa State University, USA
We demonstrate equivalence between 3D bulk optics and certain 2D metasurfaces, where phase delay arises from trains of Lorentzian resonances in the effective sheet conductivities, instead of propagating phase accumulation. We show perfectly achromatic sheet versions of prisms and lenses with arbitrary spectral bandwidth and dual reflection/transmission operation.
17:00 - 17:15 - Theory and Application of Analytical Models for Thin-Wire Nanoloop Antennas Oral [Show abstract]
  • Ryan J. Chaky, Department of Electrical Engineering, The Pennsylvania State University, USA
  • Douglas H. Werner, Department of Electrical Engineering, The Pennsylvania State University, USA
Analytical models for plasmonic structures are desirable in lieu of full-wave simulations. Though these models cannot be derived for all complex structures, an exact model for nanoloop antennas has been recently developed. This paper presents a demonstration of the theory in the design of directive and reconfigurable loaded nanoloop antennas.
17:15 - 17:30 - Efficient Light Trapping in the Infrared using Gold - Black Phosphorus Nanostructured Absorbers Oral [Show abstract]
  • Romil Audhkhasi, University of Southern California, USA
  • Michelle Povinelli, University of Southern California, USA
We propose a gold – based nanostructured design for achieving enhanced absorption in ultrathin black phosphorus (BP) layers in the 3 – 5 μm wavelength range. By suitably tuning the design parameters, we are able to excite strongly localized modes in BP layers of thicknesses ranging from 5 to 50 nm at a wavelength of 4 μm. We test the efficiency of these absorbers by computing their absorption enhancement factor and comparing it against the conventional 4n2 limit. For a BP layer thickness of 5 nm, we are able to achieve an enhancement of 561 at a wavelength of 4 μm, which is significantly greater than the conventional value of 4n2 equal to 34 for an isolated textured BP layer.
17:30 - 17:45 - Luminescence Enhancement of Coupled Dielectric Mie Resonators Oral [Show abstract]
  • Viktoriia Rutckaia, Advanced Science Research Center at The Graduate Center of the City University of New York, USA
  • Frank Heyroth, Interdisciplinary center of material science, Martin-Luther-University of Halle-Wittenberg, Germany
  • Alexey Novikov, Institute for Physics of Microstructures of the Russian Academy of Sciences, Russia
  • Mikhail Shaleev, Institute for Physics of Microstructures of the Russian Academy of Sciences, Russia
  • Roman Savelev, Department of Nanophotonics and Metamaterials, ITMO University, Russia
  • Joerg Schilling, Centre for Innovation Competence SiLi-nano, Martin-Luther-University of Halle-Wittenberg, Germany
  • Mihail Petrov, Department of Nanophotonics and Metamaterials, ITMO University, Russia
Embedding Ge-quantum dot emitters in Mie resonators leads to an enhancement of their luminescence efficiency due to the Purcell effect. To increase this effect, collective Mie resonances in extended Mie-resonator chains are investigated leading to a partial cancellation of radiation losses and experimentally observed Q-factors of up to 500. The corresponding modes and their field localization are theoretically analysed and traced back to a combination of individual oscillating dipoles.
17:45 - 18:15 - Control of light-matter interaction in 2D materials using artifical photonic media Invited oral [Show abstract]
  • Vinod Menon, City College - CUNY, USA
In this talk we will present an overview of our work on control of light matter interaction in 2D materials using microcavities and metamaterials. Specifically, we will discuss systems that show strong light-matter coupling and enhance single photon emission.
16:00 - Special session: Metamaterials in civil and maritime engineering

Organizer(s): Bogdan Ungureanu; Sebastien Guenneau; Stephane Brule

Session chairperson(s): Yu-Gui Peng

16:00 - 16:15 - Hierarchical Large-Scale Elastic Metamaterials as an Innovative Passive Isolation Strategy for Seismic Wave Mitigation Oral [Show abstract]
  • Marco Miniaci, CNRS, Centrale Lille, ISEN, Univ. Lille, Univ. Valenciennes, UMR 8520 - IEMN, F-59000 Lille, France, France
  • Nesrine Kherraz, University of Torino, Department of Physics, Via Pietro Giuria 1, 10125, Torino, Italy, Italy
  • Federico Bosia, Politecnico di Torino, Department of Applied Science and Technology, Corso Duca degli Abruzzi 24, 10124 Torino, Italy, Italy
  • Antonio Salvatore Gliozzi, Politecnico di Torino, Department of Applied Science and Technology, Corso Duca degli Abruzzi 24, 10124 Torino, Italy, Italy
  • Miguel Onorato, University of Torino, Department of Physics, Via Pietro Giuria 1, 10125, Torino, Italy, Italy
  • Nicola Maria Pugno, University of Trento, Laboratory of Bio-Inspired, Bionic, Nano, Meta Materials & Mechanics, Department of Civil, Environmental and Mechanical Engineering, Via Mesiano77, 38123 Trento, Italy, Italy
Large scale elastic metamaterials as an innovative passive isolation strategy for seismic waves has recently attracted increasing interest in the scientific community. In this work, we investigate the feasibility of an innovative design based on hierarchical organization of the unit cell, i.e. a structure having a self-similar geometry repeated at different scale levels. Results show how the introduction of hierarchy allows the conception of unit cells exhibiting reduced size while attaining good isolation efficiency at frequencies of interest for earthquake engineering.
16:15 - 16:30 - Regular Sloshing Modes in the Irregular Cavity Using Metabathymetry Oral [Show abstract]
  • Adam Anglart, PMMH, ESPCI Paris - PSL, France
  • Agnès Maurel, Institut Langevin, France
  • Philippe Petitjeans, PMMH, ESPCI Paris - PSL, France
  • Vincent Pagneux, Laboratoire d'Acoustique de l'Université du Maine, France
We demonstrate experimentally and numerically that metamaterials can be used to control water wave propagation and resonance properties of a closed cavity. Experimental data show the capability of water-wave metamaterials to provide a robust anisotropic medium for water wave propagation.
16:30 - 16:45 - Asymmetrical Water Waves Wakes due to an Anisotropic Bathymetry Oral [Show abstract]
  • Léo-Paul Euvé, Laboratoire Physique et Mécanique des Milieux Hétérogènes (Ecole Supérieure de Physique et de Chimie Industrielles de la Ville de Paris), France
  • Agnès Maurel, Institut Langevin (Ecole Supérieure de Physique et de Chimie Industrielles de la Ville de Paris), France
  • Vincent Pagneux, Laboratoire d’Acoustique de l’Université du Mans, France
  • Philippe Petitjeans, Laboratoire Physique et Mécanique des Milieux Hétérogènes (Ecole Supérieure de Physique et de Chimie Industrielles de la Ville de Paris), France
We show, experimentally and numerically, that the wake of a ship becomes highly asymmetrical when the bathymetry is varying periodically. This bathymetry forms a metamaterial modifying the properties of the waves (wavenumber, speed) depending on the direction toward which they propagates.
16:45 - 17:00 - Topological Beam Splitting for Seismic Waves in Perforated Plates Oral [Show abstract]
  • Bogdan Ungureanu, Imperial College London, United Kingdom
  • Mehul Makwana, Imperial College London, United Kingdom
  • Richard Craster, Imperial College London, United Kingdom
  • Sébastien Guenneau, UMI 2004 Abraham de Moivre-CNRS, Imperial College London, United Kingdom
We propose a passive wave splitter, created purely by geometry, to engineer three-way beam splitting for flexural waves in thin plates. We do so by considering a square perforation within a cell that is then extended periodically upon a square lattice. To achieve splitting and transport around a sharp bend we use accidental, and not symmetry-induced, Dirac cones, upon rotation of the square perforation in the periodic cell. The theory is developed and full scattering finite element simulations demonstrate the effectiveness of the proposed designs. Such elastic plate systems have potential applications ranging from ultrasonics to geophysics.
17:00 - 17:15 - Seismic Phononic Crystals via Decoupled Elastodynamic Navier Equation Oral [Show abstract]
  • Dongwoo Lee, Pohang University of Science and Technology, Korea (South)
  • Junsuk Rho, Pohang University of Science and Technology, Korea (South)
The phenomenon, known as a complete band gap in photonic crystals consisting of periodically arranged man-made nano structures, caused a huge sensation in photonics. Inspired by the physical methodology, we extend it to large-scale wave propagation for seismic waves. In particular, we exploit the elastodynamic Navier equation in the medium for seismic phononic crystals to induce complete band gaps of body (P) and shear (S) waves. We also show a technique that uses weak formulations to analyze band structures. Estimation of evanescent modes by complex-valued wave vectors yields propagation length, then we redesign bulky phononic crystals to be as thin as possible.
17:15 - 17:30 - Dynamical Properties of a Periodic Mass-Spring Nonlinear Seismic Metamaterial Oral [Show abstract]
  • Roberto Zivieri, University of Messina, Italy
The amplitude and the period of the rectangular distribution are derived from the matching between the ansatz and the exact solution of the equation in a periodic and anharmonic mass-spring system. These results could be employed for the analysis and modeling of seismic metamaterials in composite foundations.
17:30 - 17:45 - Conceptual Development of Vibroacoustic Metamaterial Structures for Thin-Walled Composite Structures for Aerospace Applications Oral [Show abstract]
  • Daria Manushyna, Fraunhofer Institue for structural durability and system reliability LBF, Germany
An approach for conceptual development for vibroacoustic metamaterial structures for realization in aerospace applications is presented. Vibration reduction in the frequency range up to 500 Hz has been evaluated for a composite launcher interstage, designed as a vibroacousitc metamaterial structure based on the local resonance effect. Aspects as numerical design, relevant design parameters and manufacturing requirements addressed in this paper.
17:45 - 18:00 - Recent Advances in Metamaterials for Flexural Gravity Waves in Thin Floating Plates Oral [Show abstract]
  • Mohamed Farhat, King Abdullah University of Science and Technology (KAUST), Saudi Arabia
  • Sebastien Guenneau, Imperial College London, United Kingdom
  • Ying Wu, King Abdullah University of Science and Technology (KAUST), Saudi Arabia
<p> We present advances for flexural-gravity, by coupling bending in thin-plates to linearized water-waves. First, we show that scattering of flexural-gravity waves results in non-vanishing scattering cross-section in the zero-frequency limit and propose ways for cloaking. Second, we demonstrate the existence of exceptional points and asymmetric scattering in PT-symmetric floating structures.</p>
16:00 - Special session: Modelling and Computation of Optics in Artificial Media

Organizer(s): Amir Sagiv; Michael Weinstein

Session chairperson(s): Sander Mann

16:00 - 16:30 - Inverse Design of Optical Metasurfaces Invited oral [Show abstract]
  • Steven G. Johnson, Massachusetts Institute of Technology, USA
  • Zin Lin, Massachusetts Institute of Technology, USA
  • Raphael Pestourie, Massachusetts Institute of Technology, USA
Optical metasurfaces are thin large-area structures with aperiodic subwavelength patterns, designed for focusing light and a variety of other wave transformation. Because of their irregularity and large scale, they are one of the most challenging tasks for computational design. This talk will present ways to harness the full computational power of modern large-scale optimization in order to design metasurfaces with thousands or millions of free parameters. We exploit various methods of domain-decomposition approximations, supercomputer-scale topology optimization, laptop-scale “surrogate” models based on Chebyshev interpolation or new active-learning neural networks, and other techniques to attack challenging problems: achromatic lenses that simultaneously handle many wavelengths and angles, “deep” images, hyperspectral imaging, and active structures.
16:30 - 16:45 - Topologically Protected Wave Motion Along Curved Edges Oral [Show abstract]
  • Yi Zhu, Tsinghua University, China
  • Pipi Hu, Tsinghua University, China
<p> In this talk we focus on the 2 dimensional Dirac-Weyl equation with a sign-change mass along a curved edge. We construct explicit quasi-traveling wave solutions to this equation for circular edges and slowly varying straight edges. We prove such solutions are asymptotically stable with an energy estimate. We also provide many numerical simulations to demonstrate our constructions and estimates independently.</p>
16:45 - 17:00 - Lightning-fast Solution of Scattering Problems in nanophotonics: an Effortless Modal Approach Oral [Show abstract]
  • Parry Y. Chen, Ben-Gurion University, Israel
  • Egor Muljarov, Cardiff University, UK
  • Yonatan Sivan, Ben-Gurion University, Israel
We describe a generalized normal modal expansion (GENOME) for electromagnetic problems based on eigenpermittivity modes. We demonstrate that our method is significantly faster, more accurate and robust than other scattering and modal methods. As a demonstration, we study the Green's tensor of various complex scatterers and study quantum photonic phenomena like the Purcell effect and FRET enhanced by the scatterers.
17:00 - 17:15 - Time-Domain Simulation of Dispersive Maxwell's Equations with Application to Optical Metamaterial Design Oral [Show abstract]
  • Jeffrey Banks, Rensselaer Polytechnic Institute, USA
This talk focuses on time-domain simulation of dispersive optical materials. Our approach is based on the second-order formulation of Maxwell's equations, and uses auxiliary differential equations to evolve the wave polarization vectors for a generalized dispersion material model, with material parameters determined to fit the frequency domain material response.
17:15 - 17:30 - Discrete Approximation of Topologically Protected Modes in Magneto-optical Media Oral [Show abstract]
  • Mark Ablowitz, University of Colorado Boulder, USA
  • Justin Cole, University of Colorado Colorado Springs, USA
A two-dimensional periodic array of ferrite rods with an external magnetic field applied to them is studied. The formidable nature of this problem motivates a discrete reduction through an expansion in terms of exponentially localized Wannier modes. The topological nature of the problem prevents a direct application of the Wannier functions, so a perturbative approach is developed to find a suitable basis. The discrete model produces states which have nontrivial topological Chern invariants. Edge modes are found that propagate unidirectionally and do not backscatter at lattice defects.
17:30 - 17:45 - Existence and Computation of Exponentially Localized Wannier Functions for Non-Periodic Insulators in Two Dimensions and Gigher Oral [Show abstract]
  • Alexander Watson, Duke University, USA
  • Kevin Stubbs, Duke University, USA
  • Jianfeng Lu, Duke University, USA
<p> Wannier functions, spatially localized basis functions for the Fermi projection, are a fundamental tool in the study of materials’ electronic properties. Conditions guaranteeing existence of exponentially localized Wannier functions in one, two and three-dimensional crystalline insulators are now rigorously known. It is expected that, under appropriate assumptions, similar results will hold for non-periodic insulators e.g. crystalline insulators with local defects. So far, such results have been proven in one dimension by Nenciu-Nenciu (following Kivelson). In this talk I will present rigorous proof of a generalization of Nenciu-Nenciu’s result to two dimensions and higher, where the situation is significantly more complex and new ideas are necessary. I will also discuss ramifications of our result for numerical computation. Joint work with Kevin Stubbs and Jianfeng Lu (Duke).</p>
17:45 - 18:00 - The Smallest Mode Volume of a Dielectric Resonator Oral [Show abstract]
  • Qingqing Zhao, Yale University, Hong Kong University, USA
  • Owen Miller, Yale University, USA
<p> We show that Lagrangian duality can be used to identify the smallest possible mode volume of any dielectric resonator, knowing only the available material refractive index. This technique can identify bounds subject to two constraints that had not been feasible to incorporate into any previous bound approach: minimum feature size (without which the bounds would trivially converge to 0) and multi-frequency operation. We use inverse design to discover 2D structures approaching their respective bounds, showing that they are tight or nearly so.</p>
16:00 - Metamaterial and metasurface antennas III

Session chairperson(s): Younes Ra'di

16:00 - 16:30 - Glide-symmetric Periodic Structures and their Applications for Microwave Electromagnetic Devices Invited oral [Show abstract]
  • Oscar Quevedo-Teruel, KTH Royal Institute of Technology, Sweden
At this conference, I will provide a brief introduction to the methods to analyze and fundamentally understand glide-symmetric structures and I will introduce a few examples of their potential for practical applications in the microwave regime with special emphasis on radar, spectroscopy and satellite and ground communications.
16:30 - 17:00 - Ka-band Antennas Designed with Cost-effective Versions of Gap Waveguide Technology Invited oral [Show abstract]
  • Eva Rajo-Iglesias, University Carlos III of Madrid, Spain
Gap waveguide technology was first proposed ten years ago. Most of the designs are based on the use of the bed of nails as periodic structure to create the required parallel plate stop band. In addition, the manufacturing is typically made by milling. In this presentation, alternative options for designing antennas in the Ka band with a simplified manufacturing gap waveguide technology will be shown.
17:00 - 17:15 - Compact Antennas in Ridge Gap Waveguide with Circular Polarization Oral [Show abstract]
  • Dayan Pérez, Public University of Navarra, Spain
  • Iñigo Ederra, Public University of Navarra, Spain
  • Miguel Beruete, Public University of Navarra, Spain
Two compact antennas in Ridge Gap Waveguide (RGW) technology, working at 60 GHz, with a high-purity circular polarization (CP) within a broad bandwidth are manufactured and measured. A great broadband matching with reflection coefficient magnitude and CP is achieved. The maximum gain in both designs is 5.49 and 11.12 dB respectively.
17:15 - 17:30 - How to Decouple and Cloak Interleaved Phased Arrays? Oral [Show abstract]
  • Hossein Mehrpour Bernety, University of Utah, USA
  • Shefali Pawar, University of Mississippi, USA
  • Harry G. Skinner, Intel Corporation, USA
  • Seong-Youp Suh, Intel Corporation, USA
  • Andrea Alù, Advanced Science Research Center, City University of New York, USA
  • Alexander B. Yakovlev, University of Mississippi, USA
<p> In this paper, we show how metasurface cloaks can be used for decoupling and cloaking of interleaved planar phased arrays operating at neighboring frequencies. Accordingly: (a) the two arrays occupy one quarter of the area they would occupy in the case of being separated traditionally and (b) The arrays operate independently, and beam scanning can be achieved with frequency diversity. In this regard, the arrays act as if they were isolated and do not sense the presence of each other.</p>
17:30 - 17:45 - Advances in Mathematical Analysis and Simulation of Invisibility Cloaks with Metamaterials Withdrawn [Show abstract]
  • Jichun Li, University of Nevada Las Vegas, USA
The study of invisibility cloak with metamaterials has attracted great interests since 2006. In this article, we review the transformation-based electromagnetic cloaking models and the corresponding mathematical results we obtained in recent years.
17:45 - 18:00 - Switchable Eleven-State Bandpass Filter with Multiple Split-Ring Resonators No show [Show abstract]
  • Marko Ninic, Novelic d.o.o., Serbia
  • Branka Jokanovic, Academy of Engineering Sciences of Serbia, Serbia
We present an extremely compact quad-band filter which consists of four split-ring resonators (SRRs) placed concentrically one inside the other. Switchable version of this filter is achieved by switching-off either single or multiple SRRs using PIN diodes which are placed on the vertical branches of SRRs. In that way different triple-band, dual-band and single-band configurations from the initial quad-band topology. Measured performances of the proposed multi-state filter are in very good agreement with simulations.
16:00 - Homogenization and effective medium models

Session chairperson(s): Christian Kern

16:00 - 16:30 - Broadband Uniaxial Dielectric-Magnetic Metamaterial with Giant Anisotropy Factor Invited oral [Show abstract]
  • Juan D. Baena, Universidad Nacional de Colombia, Colombia
  • Juan P. del Risco, Universidad Nacional de Colombia, Colombia
  • Ana C. Escobar, Universidad Nacional de Colombia, Colombia
In this paper a periodic array of metal patches with glide symmetry is studied. It was found that it is a broadband uniaxial dielectric-magnetic medium with giant anisotropic factors. The transverse components of permittivity and permeability tensors are much bigger than the axial ones. Simple but accurate formulas have been provided for them.
16:30 - 17:00 - Multiple Scale Method Applied to Homogenization of Irrational Metamaterials Extended oral [Show abstract]
  • Sebastien Guenneau , UMI Abraham de Moivre-CNRS, Imperial College London, United Kingdom
  • Frederic Zolla, Aix Marseille Université, CNRS, Centrale Marseille, Institut Fresnel , France
  • Elena Cherkaev , University of Utah, United States
  • Niklas Wellander, Swedish Defence Research Agency (FOI), Sweden
Multiscale homogenization method is developed for irrational metamaterials in the quasiperiodic (cut-and-projection) setting. We project partial differential operators acting on periodic functions in higher-dimensional space onto operators acting on quasiperiodic functions in the physical space. The method allows us to replace heterogeneous quasiperiodic structures by homogeneous media with anisotropic permittivity and permeability tensors, obtained from solving annex problems in higher dimensional space.
17:00 - 17:15 - On the Correct Definition of Polarization for Metamaterials Oral [Show abstract]
  • Juan Domingo Baena Doello, National University of Colombia, Colombia
To compute the electric dipole moment, there are two classical ways: from the charge density or from the current density. Although both ways are equivalent for the case of a local source, they are different when the current density touches the boundary of the integration volume, as may happen for some unit cells of periodic structures. In this paper, we study what is the best choice in order to get the macroscopic polarization of a periodic metamaterial.
17:15 - 17:30 - Fast Retrieval of Effective Material Parameters Using Artificial Neural Network Oral [Show abstract]
  • Taavi Repän, Karlsruhe Institute of Technology, Germany
  • Carsten Rockstuhl, Karlsruhe Institute of Technology, Germany
We propose an approach based on neural networks to enable fast retrieval of effective material properties, avoiding the need of costly numerical fitting procedures. The key to our approach is an automated approach to subdivide the parameter space into subspaces, where the parameter retrieval problem is unique and can thus be learned effectively with neural networks.
17:30 - 17:45 - On the Range of Effective Complex Electrical Permittivities of Isotropic Composite Materials Oral [Show abstract]
  • Christian Kern, University of Utah, USA
  • Owen D. Miller, Yale University, USA
  • Graeme W. Milton, University of Utah, USA
We identify the range of complex permittivities of isotropic composite materials made from two isotropic components by deriving corresponding bounds and identifying microstructures attaining these bounds. As a consequence, we obtain the range of absorption in such materials.
17:45 - 18:00 - Higher Order Nonlocal Constitutive Relations To Homogenize Metamaterials Oral [Show abstract]
  • Fatima Z. Goffi, Karlsruhe Institute of Technology, Germany
  • Ramakrishna Venkitakrishnan, Karlsruhe Institute of Technology, Germany
  • Michael Plum, Karlsruhe Institute of Technology, Germany
  • Carsten Rockstuhl, Karlsruhe Institute of Technology, Germany
  • Andrii Khrabustovskyi, University of Hradec Králové, Czech Republic
For homogenizing metamaterials, nonlocal constitutive relations are obtained while approximating the general response function up to order 2N. Dispersion relations are discussed and the corresponding interface conditions that support the constitutive relations are derived with a weak formulation. Details are given for the sixth order term of the approximation.
1 October 2020 / Start time: 9 h 0 min
09:00 - 10:00 - Plenary Session IV
09:00 - Plenary session IV

Session chairperson(s): Andrea Alu

09:00 - 10:00 - Next generation photonics Plenary [Show abstract]
  • Michal Lipson, Columbia University, USA
We are now experiencing a revolution in optical technologies: in the past the state of the art in the field of photonics transitioned from individual miniaturized optical devices to massive optical circuits on a microelectronic chip that can be modified on demand. This revolution is ongoing –new materials and technologies are emerging to control the flow of light in unprecedented ways and it is opening the door to applications that only a decade ago were unimaginable.
10:00 - 10:30 - Coffee Break (Thursday Morning)
10:30 - 12:30 - Oral Sessions (Thursday Morning)
10:30 - Special session: Designer Metasurfaces for Nonlinear Optics

Organizer(s): Yehiam Prior

Session chairperson(s): Stefano Vellucci

10:30 - 11:00 - Designing Metasurfaces for Optimal Nonlinear Optical Response Invited oral [Show abstract]
  • Yehiam Prior, Weizmann Institute of Science, Israel
<p> Nonlinear optical processes have been traditionally studied in molecular systems where one tunes the laser frequencies to the molecular energy levels for resonance enhancements. With metasurfaces one can do the reverse, namely for fixed laser frequencies the ‘system’ is tuned to be resonant with the laser frequencies. The resonant local field enhancements in such systems, typically connected to surface plasmons, enable the design of nanoscale nonlinear optical components, which, in turn, can be integrated into novel nanophotonic devices. Various approaches to surface optimization will be reviewed.</p>
11:00 - 11:15 - Resonant Wavefront-Shaping Metasurfaces Based on Quasi-Bound States in the Continuum Oral [Show abstract]
  • Nanfang Yu, Columbia University, USA
We experimentally demonstrate dielectric metasurfaces that support spatially tailored dark modes (quasi-Bound States in the Continuum) and mold optical wavefronts only at narrowband Fano resonances, while leaving the rest of the spectrum unaffected.
11:15 - 11:30 - Advances in THz Generation by Nonlinear Metasurfaces Oral [Show abstract]
  • Tal Ellenbogen, Tel-Aviv University, Israel
Recently it was shown that nonlinear metasurfaces can be used to generate broadband THz radiation. Here I will discuss different generation mechanisms, their selection rules, and show that complete spatiotemporal control over the polarization and phase of the THz waves is obtained, allowing a new class of functional THz emitters.
11:30 - 11:45 - Predicting and Understanding Nonlinear Optical Properties of Exciton-plasmon Nanomaterials Oral [Show abstract]
  • Maxim Sukharev, Arizona State University, USA
<p> We combine computational electrodynamics for propagating plasmon-polaritons with quantum approach for quantum emitters and develop a microscopic physical model of exciton-plasmon nanomaterials. We scrutinize optical properties of exciton-plasmon systems under strong coupling conditions by coupling Maxwell’s equations to nonlinear hydrodynamic model for metal and Liouville-von Neumann equations describing quantum emitters. The model is used to describe second harmonic generation in periodic arrays of nanoholes coupled to quantum emitters. It is shown that both the Coulomb interaction of conduction electrons and the convective term contribute on equal footing to the nonlinear response of metal. We also demonstrate that the energy conversion efficiency in the second harmonic process is the highest when the system is pumped at the localized surface plasmon resonance. When quantum emitters are placed on a surface of an array the lineshape of the second harmonic exhibits three peaks corresponding to second harmonics of the plasmon mode and upper and lower polaritonic states.</p>
11:45 - 12:00 - Nonlinear Dielectric Metasurfaces: Towards High Efficiency and Full Spatial Phase Control Oral [Show abstract]
  • Thomas Zentgraf, Paderborn University, Germany
  • Bingyi Liu, Harbin Institute of Technology, China
  • Bernhard Reineke, Paderborn University, Germany
  • Basudeb Sain, Paderborn University, Germany
  • Ruizhe Zhao, Beijing Institute of Technology, China
  • Lingling Huang, Beijing Institute of Technology, China
  • Yongyuan Jiang, Harbin Institute of Technology, China
<p> Metasurfaces are ideally suited for nonlinear optical processes due to their relaxation of the phase-matching condition. This opens the possibility to generate and alter the wavefront of nonlinear harmonic generation beams. However, the short propagation distance through the metasurface limits the conversion efficiency. Here, we discuss concepts of tailoring the spatial phase together with high efficiency of harmonic signals generated by silicon metasurfaces.</p>
12:00 - 12:15 - Engineering Collective Effects in Nonlinear Metasurfaces Oral [Show abstract]
  • Mikko J. Huttunen, Tampere University, Finland
  • Saad Bin-Alam, University of Ottawa, Canada
  • Yaryna Mamchur, University of Ottawa, Canada
  • Timo Stolt, Tampere University, Finland
  • Orad Reshef, University of Ottawa, Canada
  • Jean-Michel Ménard, University of Ottawa, Canada
  • Robert W. Boyd, University of Ottawa, Canada
  • Ksenia Dolgaleva, University of Ottawa, Canada
  • Martti Kauranen, Tampere University, Finland
We demonstrate a plasmonic metasurface operating near the telecommunications C band exhibiting a record-high quality factor exceeding 2000. Motivated by this demonstration, we will also present numerical predictions suggesting that such nonlinear metasurfaces could soon answer the existing demand for miniaturized and/or flat nonlinear components.
12:15 - 12:30 - Ferroelectric Nanomaterials for Nonlinear Optics and Electro-optics Oral [Show abstract]
  • Artemios Karvounis, ETH Zurich, Switzerland
  • Viola Valentina Vogler-Neuling, ETH Zurich, Switzerland
  • Felix Richter, ETH Zurich, Switzerland
  • Eric Dénervaud, ETH Zurich, Switzerland
  • Mariia Timofeeva, ETH Zurich, Switzerland
  • Rachel Grange, ETH Zurich, Switzerland
We present a novel type of ferroelectric nanomaterial based on barium titanate nanoparticles. Nanoparticle films of nanoscale thickness are deposited with large-scale uniformity, while support second order optical nonlinearities and electro-optic responses in the near infrared.
12:30 - 13:00 - Harmonic Generation and Photon Management at the Nanoscale in Nanoantennas and Metasurfaces Invited oral [Show abstract]
  • Costantino De Angelis, University of Brescia, Italy
Abtract
10:30 - Analytical and numerical modelling of metastructures III

Session chairperson(s): Davide Ramaccia

10:30 - 11:00 - Fundamental Limitations on Absorption and Scattering of Electromagnetic Waves Invited oral [Show abstract]
  • Mats Gustafsson, Lund University, Sweden
  • Kurt Schab, Santa Clara University, USA
  • Lukas Jelinek, Czech Technical University in Prague, Czech Republic
  • Miloslav Capek, Czech Technical University in Prague, Czech Republic
We present a general approach to determine physical bounds on electromagnetic systems such as scattering and absorption by metamaterials. The technique is based on numerical modelling combined with optimization over the induced sources. Solving a (convex) dual problem guarantees strict easy-to-calculate bounds. Numerical examples for maximum absorbed, scattered, and extincted power, directional scattering, and Purcell factor are used to illustrate the approach.
11:00 - 11:30 - Focusing on Bandwidth: Fundamental Limits to Broadband Metalensing and Scattering Engineering Invited oral [Show abstract]
  • Francesco Monticone, Cornell University, USA
In this talk, we discuss our recent efforts on deriving and elucidating bandwidth limits for some important classes of metamaterial devices. Particular attention is devoted to achromatic broadband metalenses, which are currently attracting substantial interest. We also discuss whether and how these bandwidth bounds may be relaxed or surpassed.
11:30 - 11:45 - Engineering the Electric and Magnetic Response of All-Dielectric Metasurfaces through Core-Shell Mie Resonators Oral [Show abstract]
  • Alessio Monti, Niccolò Cusano University, Italy
  • Andrea Alù, CUNY Advanced Science Research Center, USA
  • Alessandro Toscano, ROMA TRE University, Italy
  • Filiberto Bilotti, ROMA TRE University, Italy
In this contribution, we discuss two different strategies aimed at tailoring the electric and magnetic response of an all-dielectric metasurface. Specifically, we investigate the possibilities enabled by two different families of core-shell meta-atoms: concentric all-dielectric spheres and homogenous spheres covered by a reactive layer. The analysis of the scattering properties of these two classes of particles reveals intriguing effects that can be used for the design of innovative metasurfaces exploiting the entire multipolar response of their meta-atoms. Several examples are considered and investigated both analytically and numerically.
11:45 - 12:00 - A New Spectral Element Method for One Dimensional Photonic Structures Oral [Show abstract]
  • Gerard Granet, Institut Pascal, Université Clermont Auvergne, France
We report on the derivation of a spectral element method the originality of which comes from the use of modified Legendre polynomials. The method is easy to implement and it behaves much better for plasmonic structures than the widely used Fourier Modal Method .
12:00 - 12:15 - Maximal Single-Frequency Electromagnetic Response Oral [Show abstract]
  • Zeyu Kuang, Yale Applied Physics, USA
  • Lang Zhang, Yale Applied Physics, USA
  • Owen D. Miller, Yale Applied Physics, USA
<p> We develop an analytical framework to derive upper bounds to single-frequency electromagnetic response. It unifies previous theories on optical scattering bounds and reveals new insight for optimal nanophotonic design, with applications including far-field scattering, near-field local-density-of-states engineering, and the design of perfect absorbers.</p>
12:15 - 12:30 - Lattice Resonances in Metasurfaces Composed of Silicon Nano-Cylinders Oral [Show abstract]
  • Saeid Jamilan, Michigan Tech, USA
  • Elena Semouchkina, Michigan Tech, USA
<p> We investigate lattice resonances (LRs) in metasurfaces (MSs), composed of silicon nano-cylinders. It is revealed that LRs can be detected through concentration of fields at specific locations in the gaps between nano-cylinders. Formation of LRs appears to significantly modify the resonance responses of MSs, transforming elementary responses into collective phenomena. Their contribution in red-shifting of resonances at increasing the lattice constants and in phenomena, associated with Rayleigh anomalies, are discussed. It is demonstrated that the coincidence of electric and magnetic resonances at the presence of LRs is not imperative for realizing the Kerker’s effects.</p>
10:30 - Plasmonics III

Session chairperson(s): Mirko Barbuto

10:30 - 11:00 - What is the Best Medium for Sub-Wavelength Field Enhancement? Invited oral [Show abstract]
  • Jacob Khurgin, Johns Hopkins University, USA
Ability to concentrate the electrical field into the sub-wavelength volumes is the key benefit sought and to a certain degree found within the discipline of plasmonics. This ability is restricted only by the ohmic loss in the noble metals and as of recently in the infrared region metals are beginning to face a challenge from the emerging alternative media: phononic (i.e. relying on surface phonon polaritons) and photonic (i.e. relying on high refractive index) all-dielectric structures and highly doped semiconductors, all of them having smaller intrinsic loss than metals. In this work we perform comparison of the degree of enhancement and its spectral selectivity for different media and confirm that while one can obtain sharper resonant features with all-dielectric structures, the magnitude of the field enhancement is invariably higher with metals like gold and copper primarily due to higher density of electrons there. In the end, depending on application, metals and dielectrics have their own unique advantages.
11:00 - 11:15 - Theory of Electron Energy-Loss Spectroscopy in Atomically Thin Metallic Films Oral [Show abstract]
  • Alvaro Rodriguez Echarri, ICFO - The institute of Photonic Sciences, Spain
  • Enok Johannes Haahr Skjølstrup, Department of Materials and Production, Aalborg University, Skjernvej 4A, DK-9220 Aalborg East, Denmark
  • Thomas G. Pedersenand, Department of Materials and Production, Aalborg University, Skjernvej 4A, DK-9220 Aalborg East, Denmark
  • Javier García de Abajo, ICFO - The institute of Photonic Sciences, ICREA – Institució Catalana de Recerca i Estudis Avançats, Passeig Lluís Companys 23, 08010 Barcelona, Spain
A quantum mechanical model is used to study EELS from crystalline noble metal films, which show intrinsic features associated with their crystallographic orientation.
11:15 - 11:30 - Near-Field Luminescence of Two-Dimensional Semiconductors Oral [Show abstract]
  • Vlastimil Křápek, Brno University of Technology, Czech Republic
  • Petr Dvořák, Brno University of Technology, Czech Republic
  • Lukáš Kejík, Brno University of Technology, Czech Republic
  • Martin Konečný, Brno University of Technology, Czech Republic
  • Zoltán Édes, Brno University of Technology, Czech Republic
  • Martin Hrtoň, Brno University of Technology, Czech Republic
  • Michal Kvapil, Brno University of Technology, Czech Republic
  • Michal Horák, Brno University of Technology, Czech Republic
  • Tomáš Šikola, Brno University of Technology, Czech Republic
Two-dimensional semiconductors are ideal light sources for on-chip integration. To overcome the diffraction-limited spatial resolution, near-field handling of the emission would be essential. We present fully near-field luminescence study of two-dimensional semiconductors, with a surface plasmon interference device used for the excitation and scanning near-field optical microscopy for the collection.
11:30 - 11:45 - Metasurface Quantum Well Photodetectors with Broadened Photoresponse Using a Patchwork of Cavities within a Subwavelength Period Oral [Show abstract]
  • Mel Hainey, Jr., National Institute for Materials Science, Japan
  • Takaaki Mano, National Institute for Materials Science, Japan
  • Takeshi Kasaya, National Institute for Materials Science, Japan
  • Yoji Jimba, Nihon University, College of Engineering, Japan
  • Hiroshi Miyazaki, Tohoku University, Department of Applied Physics, Japan
  • Tetsuyuki Ochiai, National Institute for Materials Science, Japan
  • Hirotaka Osato, National Institute for Materials Science, Japan
  • Kazuhiro Watanabe, National Institute for Materials Science, Japan
  • Yoshimasa Sugimoto, National Institute for Materials Science, Japan
  • Takuya Kawazu, National Institute for Materials Science, Japan
  • Yukinaga Arai, National Institute for Materials Science, Japan
  • Akitsu Shigetou, National Institute for Materials Science, Japan
  • Hideki T. Miyazaki, National Institute for Materials Science, Japan
We demonstrate the design and fabrication of a square cavity metasurface QWIP with high signal-to-noise ratio, which serves as the basis for detectors made from a patchwork of square cavities that absorb across the full spectral range of the quantum well. Absorption behavior follows previous metasurface absorber reports, indicating this process and device structure can be a roadmap for developing next-generation detectors.
11:45 - 12:00 - Entangled Quantum Emitters in the Presence of a Metallic Nanodisk Oral [Show abstract]
  • Vasilios Karanikolas, NIMS, Japan
Ultra-thin noble metal nanodisks facilitate high entanglement between distant quantum emitters (QEs). The ultra-thin noble metal nanodisk supports localized plasmon resonances; when these modes are excited and high coupling values between a pair of QEs are observed. We present that the entanglement time of the QEs surpasses the relaxation time of the individual QEs interacting with the metallic disk and reach the steady state faster than the case the QE are placed in free-space.
12:00 - 12:15 - Thermo-Optical Nonlinearity of Metallic Nanoparticle(s) Oral [Show abstract]
  • Ieng-Wai Un, School of Electrical and Computer Engineering, Ben-Gurion University of the Negev, Israel, Israel
  • Yonatan Sivan, School of Electrical and Computer Engineering, Ben-Gurion University of the Negev, Israel, Israel
We study the thermo-optical nonlinearity of a single metal nanoparticle and many-nanoparticle composite under continuous-wave illumination. This study is an important step towards a better understanding of the role of thermal effects in single-nanoparticle systems and in multiple-nanoparticle systems under intense illumination.
12:15 - 12:30 - Sum Frequency Generation From Single Nanopatricles: A transformation Optics Approach Oral [Show abstract]
  • Shimon Elkabetz, Ben-Gurion University, Israel
  • K. N. Reddy, Ben-Gurion University, Israel
  • P. Y. Chen, Ben-Gurion University, Israel
  • A.I. Fernandez-Domınguez, Universidad Autonoma de Madrid, Spain
  • Y. Sivan, Ben-Gurion University, Israel
<p> We study analytically frequency conversion in subwavelength nanoparticles usingtransformation optics from a singular geometry of touching plasmonic wires. We obtain analyticsolutions of the near field, and unlike previous studies of these structures, we complement itwith a solution of the far field properties. Our investigation revealed that apart from the mode-matching condition, the phase-matching condition plays a major role even for subwavelengthstructures. In addition, unexpectedly, a new and highly influential component was discovered.We further focus on three wave mixing process and show a superiority to the degenerate (secondharmonic) case, SH is dominant for near and far field. This investigation enables optimizing thefrequency conversion process</p>
12:30 - 13:00 - Plasmonic hot-careers: Energy spectrum revealed via single molecule transport Invited oral [Show abstract]
  • V.M. Shalaev, Purdue University, USA
  • H. Reddy, Purdue University, USA
  • K. Wang, University of Michigan, USA
  • Z. Kudyshev, Purdue University, USA
  • L. Zhu, University of Michigan, USA
  • S. Yan, University of Michigan, USA
  • A. Vezzoli, University of Liverpool, United Kingdom
  • S. J. Higgins, University of Liverpool, United Kingdom
  • V. Gavini, University of Michigan, USA
  • A. Boltasseva, Purdue University, USA
  • P. Reddy, University of Michigan, USA
  • E. Meyhofer, University of Michigan, USA
The generation of hot-carriers in plasmonic nanostructures, via plasmon decay, is of great current interest as hot-carriers play key roles in applications like photocatalysis, energy harvesting and in novel photodetection schemes that circumvent band-gap limitations. However, experimental quantification of steady-state energy distributions of hot-carriers in plasmonic nanostructures, which is critical for systematic progress, has not been possible. In this talk, we will describe our recent experimental advances that have enabled the direct measurement of hot-carrier energy distributions under steady-state conditions [1]. Specifically, we will explain how a scanning probe-based technique that records charge transport through single molecular junctions, when combined with nanoplasmonic experimental methods, can be leveraged to directly quantify hot-carrier energy distributions in a key model system—a thin gold film that supports propagating surface plasmon polaritons. Furthermore, key physical insights from our measurements on the role of Landau damping in producing hot-carriers and the contributions of different plasmonic modes towards hot-carrier generation will be discussed. Finally, we will outline how these experimental advances could potentially be leveraged to quantify hot-carrier distributions in plasmonic nanoparticles and other nanophotonic devices.
10:30 - Noncreciprocal and topological metamaterials III

Session chairperson(s): Emanuele Galiffi

10:30 - 11:00 - Topological and Nonreciprocal Plasmonics Invited oral [Show abstract]
  • Paloma Arroyo Huidobro, Instituto de Telecomunicações - Instituto Superior Técnico, Portugal
Topological and spatio-temporal plasmonic metasurfaces enable novel effects based on “one-way” light modes. Topological plasmonic metasurfaces host spin-dependent edge states, and can also realize higher-order topological states (corner modes). Spatio-temporal modulation of the electromagnetic parameters enables broadband nonreciprocal amplification, as well as relativistic effects such as the Fresnel drag of light, even if there is no real motion of the medium.
11:00 - 11:15 - On the Dynamic Tailoring of One-Way Surface Plasmons over Drift-Biased Graphene Metasurfaces Oral [Show abstract]
  • Nayan Kumar Paul, University of California Davis, USA
  • Juan Sebastian Gomez-Diaz, University of California Davis, USA
Drift-biased graphene enables strong nonreciprocal light-matter interactions. In this work, we show that applying two longitudinal DC bias orthogonal to each other permits to greatly manipulate the isofrequency contour of the surface in a nonreciprocal manner, allowing to dynamically steer and canalize one-way plasmons towards desired directions in the plane. Through a dedicated Green’s function formalism that takes graphene’s intrinsic nonlocality into account, we demonstrate that simply controlling two bias of just a few volts enables unprecedented flexibility to synthesize a large variety of nonreciprocal and broadband electromagnetic responses over a unique physical surface. Our findings may open intriguing applications in dynamic sub-diffractive imaging and sensing systems as well as in the routing and processing of surface plasmons.
11:15 - 11:30 - The Non-Hermitian Physics of Non-Reciprocal Robotic Metamaterials Oral [Show abstract]
  • Corentin Coulais, University of Amsterdam, Netherlands
We create 1D and 2D robotic mechanical metamaterials wherein we use local control loops to break reciprocity at the level of the interactions between the unit cells to probe a wide range of non-Hermitian phenomena, ranging from the non-Hermitian skin effect, to non-Hermitian topological bulk-edge correspondence and odd-elasticity.
11:30 - 12:00 - Photonic Spin-orbit Coupling and Topological Properties of Evanescent Fields Invited oral [Show abstract]
  • Anatoly Zayats, King's College London, United Kingdom
Optical spin-orbit coupling describes how spin angular momentum of light (associated with circular polarisation of an electromagnetic wave) influences a propagation of light beam and its orbital angular momentum. The spin-orbit coupling in evanescent waves results in complex topological field structures analogous to prototypical condensed matter phenomena, such as quantum spin-Hall effect, skyrmions, merons, and others. In this talk, we will overview spin-orbit coupling, its topological manifestations and applications.
12:00 - 12:30 - Nano-optomechanical Metamaterials With Broken Spatiotemporal Symmetries Invited oral [Show abstract]
  • Ewold Verhagen, AMOLF, Netherlands
  • Javier del Pino, AMOLF, Netherlands
  • Jesse Slim, AMOLF, Netherlands
  • John Mathew, AMOLF, Netherlands
We study the emergence of nonreciprocal and topologically nontrivial phonon transport in nano-optomechanical networks, where on-chip mechanical resonators are coupled through radiation pressure. We reveal the emergence of nanomechanical circulation, helical quantum Hall states, and chiral thermal transport in phononic networks in which both time-reversal symmetry and Hermiticity are broken at will.
12:30 - 13:00 - Transition radiation by charged bunches in topological metamaterials Invited oral [Show abstract]
  • Gennady Shvets, Cornell University, USA
We demonstrate, theoretically and experimentally, that a traveling electric charge passing from one photonic crystal into another generates edge waves—electromagnetic modes with frequencies inside the common photonic band gap localized at the interface—via a process of transition edge-wave radiation (TER). A simple and intuitive expression for the TER spectral density is derived and then applied to a specific structure: two interfacing photonic topological insulators with opposite spin-Chern indices. We show that TER breaks the time-reversal symmetry and enables valley- and spinpolarized generation of topologically protected edge waves propagating in one or both directions along the interface. Experimental measurements at the Argonne Wakefield Accelerator Facility are consistent with the excitation and localization of the edge waves. The concept of TER paves the way for novel particle accelerators, detectors, and radiation sources.
10:30 - Acoustic metamaterials I

Session chairperson(s): Nikolina Jankovic

10:30 - 11:00 - Disorder-immune and Disorder-induced Transmission Resonances: Experimental Investigations using Topological Sound Invited oral [Show abstract]
  • Romain Fleury, EPFL, Switzerland
  • Farzad Zangeneh-Nejad, EPFL, Switzerland
In this talk, we describe a series of acoustic experiments using a monomode waveguide containing a finite number of cylindrical scatterers, to investigate the possibility to engineer robust scattering signatures by leveraging topological waves. We ask three kinds of questions: (i) can topology force the transmission of a given two-port system to have a given filtering response ?; (ii) to what extent and under which conditions can this response be robust to geometrical disorder ?; and (iii) can the disorder itself be a driving mechanism to force a system to perform a definite, non-random filtering operation ? Exploring these questions theoretically and experimentally, we demonstrate a rich class of physical transmission phenomena tied to topology, including symmetry-protected Lorentzian and Fano transmission spectra, as well as disorder-induced Lorentzian filters relying on randomly-drawn geometries.
11:00 - 11:30 - Simultaneous Control of Acoustic and Electromagnetic Waves Using Metasurfaces Extended oral [Show abstract]
  • Ana Díaz-Rubio, Aalto University, Finland
  • Sergei Tretyakov, Aalto University, Finland
In this work, we propose the use of metasurfaces to create multiphysics devices for simultaneous control of electromagnetic and acoustic waves. Using an analytical model based on surface impedances, we introduce power flow-conformal metasurfaces that perform the same functionality for electromagnetic and acoustic waves. Moreover, we also explore possibilities to realize different functionalities for electromagnetics and acoustics within the same platform. We numerically simulate realistic topologies for practical implementations and confirm the viability of the proposed platforms.
11:30 - 11:45 - Acoustic Materials with Target Scattering Properties Oral [Show abstract]
  • Svetlana Kuznetsova, Laboratoire d’Acoustique de l’Université du Mans, France
  • Jean Philippe Groby, Laboratoire d’Acoustique de l’Université du Mans, France
  • Luis Miguel Garcia Raffi, Instituto de Matemática pura y Applicada (IUMPA), Universitat Politècnica de València, Spain
  • Vicente Romero Garcia, Laboratoire d’Acoustique de l’Université du Mans, Spain
We report a method to design 2D acoustic materials with prescribed scattering properties. We target information in reciprocal space to construct materials the structure factor of which, i.e. the scattering pattern in the Born approximation, exactly matches the scattering properties for a set of wavelengths. In this work the material is made of a distribution of rigid cylinders embedded in air. As an example, we show 2 dimensional (2D) stealth acoustic materials showing omnidirectional and broadband back-scattering suppression. The scattering intensity is described in terms of single as well as multiple scattering formalism, showing excellent agreement with each other.
11:45 - 12:15 - Dynamics of Two-Dimensional Non-Hermitian Elastic Lattices with Non-Local Feedback Control Interactions Invited oral [Show abstract]
  • Massimo Ruzzene, University of Colorado Boulder, USA
  • Matheus I. N. Rosa, University of Colorado Boulder, USA
We investigate a family of elastic lattices where non-local feedback control interactions lead to a series of unconventional phenomena stemming from their non-Hermitian natuure. In two-dimensional lattices, the feedback interactions produce directional and non-reciprocal wave amplification, occurring in multiple frequency/wavenumber bands depending on the non-local nature of the control interactions. Moreover, the non-Hermitian skin effect manifests as modes localized at the boundaries of finite lattice strips, whose combined effect in two directions leads to the existence of bulk modes localized at corner of finite two-dimensional lattices. Our results describe fundamental properties of non-Hermitian elastic lattices, opening new possibilities for the design of active metamaterials with novel functionalities related to directional selective wave filtering, amplification and localization.
12:30 - 14:00 - Lunch Break (Thursday)
14:00 - 15:30 - Oral Sessions (Thursday Afternoon 1)
14:00 - Metamaterials with extreme parameters II

Session chairperson(s): Francesco Monticone

14:00 - 14:30 - Multiple Embedded Eigenstates in Nonlocal Plasmonic Nanostructures Invited oral [Show abstract]
  • Solange Silva, Instituto Telecomunicacoes-University of Coimbra, Portugal
  • Tiago Morgado, Instituto Telecomunicacoes-University of Coimbra, Portugal
  • Mario Silveirinha, University of Lisbon - Instituto Telecomunicacoes, Portugal
Materials with zero permittivity can fully suppress the radiation loss and enable the formation of embedded eigenstates. Here, we investigate how the spatial dispersion caused by the electron-electron interactions in a metal affects the light localization. Surprisingly, it is found that the nonlocality strongly relaxes the requirements for the observation of trapped light.
14:30 - 15:00 - Fabry-Perot Cavities and Matching Slabs Implemented in Time-Domain by Using Time-Varying Metamaterials Invited oral [Show abstract]
  • Davide Ramaccia, ROMA TRE University, Italy
  • Alessandro Toscano, ROMA TRE University, Italy
  • Filiberto Bilotti, ROMA TRE University, Italy
In this contribution, we propose the design in time-domain of two key components in electromagnetic theory, the Fabry-Perot cavity and the matching slab. Starting from the well-known reflection and transmission properties of a temporal medium discontinuity, we extend here the study to the case of the general case of multiple discontinuities, evaluating analytically the general reflection and transmission coefficients for a temporal metamaterial slab, i.e. a uniform homogeneous medium that is present in space for a limited time. It is found that the scattering response from this temporal device may be tuned to act as a temporal Fabry-Perot cavity and matching network by selecting the application time that acts like the electrical thickness for spatial slabs. Several novel devices based on temporal discontinuities can be derived by the presented concept of the temporal slab, such as temporal dielectric mirrors, broadband temporal matching networks, and temporal anomalous refraction.
15:00 - 15:15 - Temporally Modulated Non-Hermitian Optical Systems Based on Epsilon-Near-Zero Media Oral [Show abstract]
  • Zeki Hayran, Cornell University, USA
  • Francesco Monticone, Cornell University, USA
Non-Hermitian systems with judiciously designed loss and gain distributions have been shown to enable novel wave effects compared to their Hermitian counterparts. While this concept was recently extended to the temporal domain through time-varying material properties, a systematic investigation of dynamical open structures with time-varying radiation properties is still lacking, especially in the context of optical scattering. Here, we show that the radiation characteristics of a scattering system can be engineered in new ways using time-modulated epsilon-near-zero materials, leading to unique opportunities to overcome some of the limits and bounds of time-invariant system. Specifically, we demonstrate that such temporal modulations can enable novel wave effects, including unidirectional frequency transitions and bound states in the continuum that can be externally excited by broadband light sources.
14:00 - Metasurfaces II

Session chairperson(s): Alex Krasnok

14:00 - 14:30 - Metagratings Beyond Beam Manipulation Invited oral [Show abstract]
  • Vinay Kumar Killamsetty, Technion - Israel Institute of Technology, Israel
  • Liran Biniashvili, Technion - Israel Institute of Technology, Israel
  • Yaniv Kerzhner, Technion - Israel Institute of Technology, Israel
  • Oshri Rabinovich, Technion - Israel Institute of Technology, Israel
  • Ariel Epstein, Technion - Israel Institute of Technology, Israel
We present extensions of the metagrating (MG) synthesis approach to tackle a wide variety of problems in configurations other than the typical free-space diffraction engineering scenarios. It is shown that an adapted semianalytical methodology allows the design of sparse constellations of subwavelength scatterers facilitating mode conversion and seamless bending in waveguides, directive sparse antenna arrays, and formation of near-field subwavelength hot spots. These results reveal the merits of MG-inspired devices for a broad range of applications.
14:30 - 14:45 - Miniaturised Unit Cell Anisotropic LP To CP Converter Metasurface Withdrawn [Show abstract]
  • Anastasios Christodoulides, The University of Birmingham, United Kingdom
  • Kevin Mitchell, BAE Systems Air, United Kingdom
  • Alexandros Feresidis, The University of Birmingham, United Kingdom
In this paper, a design of a linear-to-circular polarization converter based on an anisotropic metasurface is presented. The proposed design is comprised of a thin polyimide layer with two dipoles arrays printed on either side and shifted appropriately and placed on top of a metal grounded substrate. This enables the conversion of a linearly polarised (LP) incident wave to a circular polarised (CP) reflected wave. Results demonstrate that the proposed anisotropic metasurface provides good angular stability. Left hand Circular polarization (LHCP) conversion for the proposed structure is realized over frequency range 9.5 GHz to 15 GHz with 3-dB-AR BW of more than of 46% for φ=0° and 37% for φ=90°.
14:45 - 15:00 - Multi-Band Waveform-Selective Metasurfaces Transmitting Continuous Waveforms Based on More Than One Frequency Oral [Show abstract]
  • Hiroki Wakatsuchi, Nagoya Institute of Technology, Japan
  • Riku Higashiura, Nagoya Institute of Technology, Japan
  • Hiroki Takeshita, Nagoya Institute of Technology, Japan
  • Daisuke Nita, Nagoya Institute of Technology, Japan
This study presents metasurfaces designed to selectively transmit electromagnetic waves even at the same frequency depending on their waveforms or pulse widths. In particular, we demonstrate such waveform-selective metasurfaces operating at several frequency bands, which leads to providing an additional selectivity of scattering control by frequency combination.
15:00 - 15:15 - Cascaded-Metasurface Non-Integer Cylindrical Bessel Beam (NIC-BB) Generator Oral [Show abstract]
  • Oscar Céspedes Vicente, Polytechnique Montréal, Canada
  • Christophe Caloz, Katholieke Universiteit (KU) Leuven, Belgium
WepresentageneratorofNon-IntegerCylindricalBesselBeams(NIC-BBs),which may find applications in communication systems, polarimetric instrumentation and particle routing. This device consists of a pair of cascaded phase-plate metasurfaces illuminated by a uniform circularly polarized wave, where the first metasurface provides the required phase dis- tribution while the second provides the required polarization distribution. It is accompanied by a powerful design procedure, which involves a unique metaparticle shape with fast axis rotated according to the geometric phase principle and Stokes parameter synthesis.
15:15 - 15:30 - Metamirror For Generation And Control Of Bessel Beam Oral [Show abstract]
  • Rui Feng, Key Laboratory of Integrated Services Networks, Xidian University, China
  • Badreddine Ratni, LEME, UPL, Univ Paris Nanterre, France
  • Jianjia Yi, School of Electronics and Information Engineering, Xi’an Jiaotong University, China
  • André de Lustrac, Université Paris-Saclay, CNRS, Centre de Nanosciences et de Nanotechnologies, France
  • Hailin Zhang, Key Laboratory of Integrated Services Networks, Xidian University, China
  • Shah Nawaz Burokur, LEME, UPL, Univ Paris Nanterre, France
Bessel beams have attracted considerable interests due to their intriguing non-diffracting and self-healing properties. Here, an electronically-engineered metamirror is designed for the flexible control of Bessel beams over a broad frequency band ranging from 9 GHz to 12 GHz. Several configurations are presented to illustrate the non-diffracting characteristics of Bessel beams. Besides, the self-healing property is verified by placing a metallic obstacle in the propagation path of the Bessel beam. Owing to the flexible manipulation capabilities, wide-bandwidth and high-efficiency properties of the reconfigurable metamirror, the proposed Bessel beam generation device opens the door to potential applications such as focusing and wireless power transmission.
14:00 - Photonic Crystal and EBG structure II

Session chairperson(s): Mohammad-Ali Miri

14:00 - 14:15 - Realization of Photonic Charge-2 Dirac Point by Engineering Super-modes in Topological Superlattices Withdrawn [Show abstract]
  • Mengying Hu, Nanjing University, China
  • Kun Ding, Imperial College, United Kingdom
  • Tong Qiao, Nanjing University, China
  • Xi Jiang, Nanjing University, China
  • Qiang Wang, Nanjing University, China
  • Shining Zhu, Nanjing University, China
  • Hui Liu, Nanjing University, China
We report on the first experimental realization of charge-2 Dirac point in the visible region by engineering hybrid super-modes in a 1-D optical superlattice system with two synthetic dimensions.Utilizing reflection and transmission measurements, we show the approach to manipulating two spawned Weyl points with identical charge and associated end modes.
14:15 - 14:30 - Design of a Hollow-Core Woodpile Waveguide Mode-Converter Oral [Show abstract]
  • Giuseppe Torrisi, Istituto Nazionale di Fisica Nucleare - Laboratori Nazionali del Sud, Italy
  • Giorgio Mauro, Istituto Nazionale di Fisica Nucleare - Laboratori Nazionali del Sud, Italy
  • Andrea Locatelli, Università degli Studi di Brescia, Italy
  • Luigi Celona, Istituto Nazionale di Fisica Nucleare - Laboratori Nazionali del Sud, Italy
  • Costantino De Angelis, Università degli Studi di Brescia, Italy
  • Gino Sorbello, Università degli Studi di Catania, Italy
In this work, the design of a dielectric hollow-core waveguide mode-converter is reported. We demonstrate that this structure can find application as high-power mode converter in Dielectric Laser Accelerators (DLAs).
14:30 - 14:45 - Realization of Gaussian Symplectic Ensemble with Quantum Spin Hall Photonic Topological Insulator Graph Oral [Show abstract]
  • Shukai Ma, Quantum Materials Center, Department of Physics, University of Maryland, USA
  • Steven Anlage, Quantum Materials Center, Department of Physics, University of Maryland, USA
The bi-anisotropic metawaveguide (BMW) is a versatile platform for realizing quantum Hall, quantum spin Hall and quantum valley Hall effects for electromagnetic waves. We utilize these photonic topological insulators (PTI) to realize a chaotic graph system whose statistical properties fall into the universality class of the Gaussian symplectic ensemble (GSE). The bonds of the graph are built with quantum spin Hall (QSH) BMW waveguides. The built-in two-fold degeneracy and time-reversal invariance make QSH-BMW systems an excellent platform to simulate the symplectic ensemble, which was first noted to describe the statistical properties of spin-1/2 time-reversal invariant chaotic systems. The spectral level spacing distribution of the PTI network eigenmodes is found to be in agreement with the predictions from the Gaussian symplectic ensemble expected for chaotic systems with such symmetry.
14:45 - 15:00 - Amplification of Light within a One-dimensional Photonic Crystal with Harmonically Oscillating Dielectric Constant of Each Layer Oral [Show abstract]
  • Tsuyoshi Ueta, The Jikei University School of Medicine, Japan
One-dimensional photonic crystals whose dielectric constant varies with time harmonically have been considered. The transmission spectra have been investigated using the perturbation method and the transfer matrix method. It has been found that the time variation of the dielectric constant amplifies the incident wave resonantly.
15:00 - 15:15 - High Sensitivity Fano-Like Rod-Type Silicon Photonic Crystal Refractive Index Sensor Oral [Show abstract]
  • Selahattin Cem KILIC, Middle East Technical University, Turkey
  • Serdar KOCAMAN, Middle East Technical University, Turkey
A rod-type silicon photonic crystal structure has been designed and numerically analyzed for the first time in a sensing application. Light-matter interaction is maximized by strong light localization in the air region, cavity Q-factor is enhanced with Fano-like resonance, and an ultra-high sensitivity up to 1039 nm/RIU is observed.
15:15 - 15:30 - Design, Fabrication and Characterization of Woodpile Photonic Crystal Waveguides Oral [Show abstract]
  • Andrea Locatelli, Università degli Studi di Brescia, Italy
  • Giorgio Mauro, Istituto Nazionale di Fisica Nucleare - Laboratori Nazionali del Sud, Italy
  • Giuseppe Torrisi, Istituto Nazionale di Fisica Nucleare - Laboratori Nazionali del Sud, Italy
  • Luigi Celona, Istituto Nazionale di Fisica Nucleare - Laboratori Nazionali del Sud, Italy
  • Costantino De Angelis, Università degli Studi di Brescia, Italy
  • Gino Sorbello, Università degli Studi di Catania, Italy
We describe the design, fabrication and characterization of woodpile photonic crystal waveguides. In particular, we fabricated hollow core waveguides in two different materials (alumina and silicon) and operating in two distinct frequency regimes (18 and 96 GHz).
14:00 - Biological and Biomedical applications of metamaterials

Session chairperson(s): Xuefeng Jiang

14:00 - 14:30 - Optical Trapping of Metasurfaces in a Microfluidic Environment Invited oral [Show abstract]
  • Meisam Askari, St Andrews University, United Kingdom
  • Blair Kirkpatrick, St Andrews University, United Kingdom
  • Tomas Cizmar, Leibniz Institute of Photonic Technology, Jena, Germany
  • Andrea Di Falco, St Andrews University, United Kingdom
We discuss the physics and applications of all-optically manipulated Photonic Metasurfaces. Flexible polymeric membranes were fabricated using electron beam lithography, subsequently suspended in a microfluidic chamber and manipulated using Holographic Optical Tweezers. Here we argue that thanks to their exceptional intrinsic stability, optically controlled photonic membranes are the ideal platform for a wide range of optomechanical and biophotonic applications.
14:30 - 15:00 - Hyperbolic Dispersion Metamaterials and Metasurfaces Invited oral [Show abstract]
  • Giuseppe Strangi, Case Western Reserve University, USA
<p> In recent years a wide interest has been spurred by the inverse design of artificial materials for nano-biophotonic applications. In particular, the extreme optical properties of artificial hyperbolic dispersion nanomaterials allowed to access new physical effects and mechanisms. The unbound isofrequency surfaces of hyperbolic metamaterials and metasurfaces allow to access virtually infinite photonic density of states, ultrahigh confinement of electromagnetic fields and anomalous wave propagation. Here, we will present the physics of different hyperbolic dispersion material geometries and how they allow to control light-matter interaction at the single nanometer scale, including within living systems.</p>
15:00 - 15:15 - Hilbert Fractal Inspired Dipoles for B1+ Field Control in Ultra-High Field MRI Oral [Show abstract]
  • Tania del Socorro Vergara Gomez, Aix Marseille Univ, CNRS, CRMBM, Marseille, France
  • Marc Dubois, Aix Marseille Univ, CNRS, Centrale Marseille, Institut Fresnel, Marseille, France
  • Kaizad Rustomji, Multiwave Imaging, Marseille, France
  • Elodie Georget, Multiwave Imaging, Marseille, France
  • Tryfon Antonakakis, Multiwave Imaging, Marseille, France
  • Stanislas Rapacchi, Aix Marseille Univ, CNRS, CRMBM, Marseille, France
  • Frank Kober, Aix Marseille Univ, CNRS, CRMBM, Marseille, France
  • Stefan Enoch, Aix Marseille Univ, CNRS, Centrale Marseille, Institut Fresnel, Marseille, France
  • Redha Abdeddaim, Aix Marseille Univ, CNRS, Centrale Marseille, Institut Fresnel, Marseille, France
The reduction of wavelengths at UH-field MRI, results in head coils B1+ field inhomogeneities. This has been effectively targeted, but challenges remain. Here, we present a new approach based on Hilbert-fractal-inspired dipoles, able to improve the B1+ field in each temporal lobe maintaining patients’ comfort and the remaining field intact.
15:15 - 15:30 - Magnetic Localized Surface Plasmons For Magnetic Resonance Imaging Applications Oral [Show abstract]
  • Carlo Rizza, CNR-SPIN, Italy
  • Elia Palange, DIIIE, University of L'Aquila, Italy
  • Angelo Galante, MESVA, University of L'Aquila, Italy
  • Marcello Alecci, MESVA, University of L'Aquila, Italy
Recently, a great deal of research efforts has been focused to realize subwavelength photonics devices for magnetic resonance imaging (MRI), one of the cornerstone diagnostic techniques in life science. We show that the excitations of magnetic localized surface plasmons (MLSPs), surface waves hosted by a subwavelength negative magnetic permeability sphere, can yield a strong enhancement of the MRI scanner performance. In addition, we demonstrate that MLSPs can be mimicked by substituting the metamaterial (MM) negative magnetic sphere with a homogeneous high-permittivity one of the same radius. Our approach overcomes several limits of the standard MM approach (generally based on effective medium theories) avoiding complex 3D fabrication procedures and removing the spatial MM inhomogeneities whose presence is detrimental in subwavelength photonics applications. Considering that RF high-dielectric homogeneous materials are available in nature, their MLSPs mimicking holds great potential in those applications based on the RF signals manipulation.
14:00 - Acoustic metamaterials II

Session chairperson(s): Yu-Gui Peng

14:00 - 14:30 - Nonreciprocal Longitudinal Vibrations of Finite Elastic Structures with Spatiotemporally Modulated Properties Invited oral [Show abstract]
  • Benjamin Goldsberry, The University of Texas at Austin, USA
  • Samuel Wallen, The University of Texas at Austin, USA
  • Michael Haberman, The, USA
Elastic metamaterials with spatiotemporally modulated material properties have received attention as a means to increase the degree of control over propagating mechanical waves in unbounded elastic media. We investigate standing elastic waves in finite structures with time- and space-dependent material properties and implications for the creation of nonreciprocal vibrational systems.
14:30 - 15:00 - Active Time-varying Acoustic Metamaterials with Digitally Virtualized Resonance Invited oral [Show abstract]
  • Jensen Li, Hong Kong University of Science and Technology, China
  • Xinhua Wen, Hong Kong University of Science and Technology, China
  • Xinghong Zhu, Hong Kong University of Science and Technology, China
We demonstrate controllable frequency conversion using time-varying acoustic metamaterials. Using digitally virtualized resonating atoms as building blocks, we construct acoustic metamaterials with arbitrary time-varying response, in either resonance strength, gain/loss parameter or resonating frequency. The high efficiency on frequency conversion is experimentally demonstrated by tailor-made time-varying response function. Its application with material gain and loss being alternating in time is also investigated.
15:00 - 15:15 - Enhanced Acoustical Transmission Through Periodic Ultrathin Resistive Sheets Oral [Show abstract]
  • Antonin Coutant, Laboratoire d'acoustique de l'Université du Mans, France
  • Yves Aurégan, Laboratoire d'acoustique de l'Université du Mans, France
  • Vincent Pagneux, Laboratoire d'acoustique de l'Université du Mans, France
We consider the scattering of acoustic waves on a set of equidistant resistive sheets. We show that at the Bragg frequency, the transmission presents an anomalously high peak. Using the transfer matrix formalism, we show that this effect occurs when the two eigenvalues of the transfer matrix coalesce, i.e. at an exceptional point. Exploiting this algebraic condition, it is possible to obtain similar anomalous transmission peaks in more general periodic media such as phononic or photonic crystals. In this context, a peak will be observed at some bandgap edges, depending on the symmetry of the wave function.
15:15 - 15:30 - Fundamental Design of Multi-Layer Fresnel Zone Plates as Ultrasonic Lens for Transcranial Treatment Oral [Show abstract]
  • Hibiki Itoga, Tokyo University of Pharmacy and Life Sciences, Japan
  • Tsuyoshi Ueta, The Jikei University School of Medicine, Japan
A method for the fundamental design of phononic lenses for transcranial ultrasound irradiation to break blood clots using holographic techniques is described. This lens is a generalized kind of Fresnel zone plates. Multi-layer FZPs as metamaterials devices are proposed and three-layer FZP shows the higher performance than that of single one.
15:30 - 15:45 - Compressibility-Near-Zero Directive Sound Oral [Show abstract]
  • Curtis Rasmussen, University of Texas at Austin, USA
  • Andrea Alù, City University of New York, USA
We show how the equivalence between a waveguide operating near cutoff and the dispersion of compressibility can lead to ideal illumination in an acoustic source. The near-zero behavior makes the source robust to disorder, which is shown using a statistical description of the radiation patterns of randomly generated geometries.
15:30 - 16:00 - Coffee Break (Thursday Afternoon)
16:00 - 18:00 - Oral Sessions (Thursday Afternoon 2)
16:00 - Special session: Nano/micro-mechanical Electromagnetic Metamaterials

Organizer(s): Kevin MacDonald; Alessandro Pitanti

Session chairperson(s): Seunghwi Kim

16:00 - 16:30 - Nanomechanical Functionalities in Photonic Metamaterials Invited oral [Show abstract]
  • Kevin MacDonald, University of Southampton, United Kingdom
  • Dimitrios Papas, University of Southampton, United Kingdom
  • Jinxiang Li, University of Southampton, United Kingdom
  • Qiang Zhang, Harbin Institute of Technology, China
  • Davide Piccinotti, University of Southampton, United Kingdom
  • Jun-Yu Ou, University of Southampton, United Kingdom
  • Eric Plum, University of Southampton, United Kingdom
  • Nikolay Zheludev, University of Southampton, United Kingdom
We review the exceptional variety of functionalities accessible by design in nanomechanical photonic metamaterials, wherein dynamic reconfiguration of sub-wavelength structure by external stimuli can yield extreme and unusual electro-, magneto-, thermo-, acousto- and nonlinear optical response characteristics.
16:30 - 16:45 - Polarization Manipulation in Dielectric Optomechanical Metasurfaces Oral [Show abstract]
  • Simone Zanotto, CNR - Istituto Nanoscienze, Italy
  • Daniel Navarro-Urrios, Universitat de Barcelona, Spain
  • Alessandro Tredicucci, Università di Pisa, Italy
  • Alessandro Pitanti, Istituto Nanoscienze, Italy
We report on design, fabrication and characterization of an optomechanical chiral dielectric metasurface capable of dynamic control of near-infrared light polarization. We show MHz polarization modulation and 350 kHz light polarimetry using the membrane fundamental drum mechanical mode.
16:45 - 17:00 - Stress-Controlled Reconfigurable Metasurface at Visible Wavelengths by MEMS Nanograting Oral [Show abstract]
  • Kentaro Iwami, Tokyo University of Agriculture and Technology, Japan
  • Yuji Koto, Tokyo University of Agriculture and Technology, Japan
  • Satoshi Ikezawa, Tokyo University of Agriculture and Technology, Japan
This paper reports retardation modulation using Au nanograting driven in out-of-plane direction by electrostatic force. By optimizing the thicknesses of sacrificial Si layer, the maximum deformation was decreased to be 61 nm, which is only 6% of the previous research. Retardation modulation of of 3.4 degree at 715 nm was measured.
17:00 - 17:15 - Ultrafast Hyperspectral Nanomotion Imaging of Ballistic and Brownian Motion in Metamaterial Nanostructures Oral [Show abstract]
  • Tongjun Liu, University of Southampton, United Kingdom
  • Jun-Yu Ou, University of Southampton, United Kingdom
  • Kevin MacDonald, University of Southampton, United Kingdom
  • Nikolay Zheludev , University of Southampton, Nanyang Technological University, United Kingdom, Singapore
The building blocks of nanomechanical photonic metamaterials are perturbed by collisions with atoms of ambient atmospheric gas and by phonons in the crystal lattice of the constituent materials. Between collisions movements are ballistic, becoming diffusive (Brownian) at longer time scales. We show how one may distinguish between these regimes using ultrafast hyperspectral SEM nanomotion imaging and discuss their manifestation in the time-dependent optical properties of the metasurfaces.
16:00 - Metamaterials for sensing

Session chairperson(s): Alex Krasnok

16:00 - 16:30 - Manipulation with Terahertz Wave Fronts Using Self-Complementary Metasurfaces Invited oral [Show abstract]
  • Vladimir Lenets, ITMO University, Russia
  • Sergei Kuznetsov, Novosibirsk State University, Russia
  • Andrey Sayanskiy, ITMO University, Russia
  • Pavel Lazorskiy, Novosibirsk State University, Russia
  • Juan Baena, Universidad Nacional de Colombia, Colombia
  • Stanislav Glybovski, ITMO University, Russia
Here we numerically demonstrate the possibility to shape a wave front in the terahertz range using a self-complementary metasurface (SCMS) with spatial modulation. A circularly polarized incident wave passing through a SCMS causes two transmitted waves, a co- and cross-polarized. The co-polarized wave, in theory, has a complex transmission coefficient of 1/2 and keeps the same front shape as the incident wave, even if the metasurface is nonuniform. On the contrary, the cross-polarized wave obtains a phase, which can be locally controlled by geometric parameters of unit cells. We apply a phase holographic method to modify the shape of the cross-polarized wave in a desirable way while keeping the co-polarized wave unchanged.
16:30 - 17:00 - A Simple All-Dielectric Metasurface-Based Cavity for Enhanced Sensing of Chiral Molecules Extended oral [Show abstract]
  • Philip Scott, Institute of Applied Physics, Karlsruhe Institute of Technology (KIT), Germany
  • Carsten Rockstuhl, Institute of Theoretical Solid State Physics, Karlsruhe Institute of Technology (KIT), 76128 Karlsruhe, Germany
  • Martin Wegener, Institute of Applied Physics and Institute of Nanotechnology, Karlsruhe Institute of Technlogy (KIT), 76128 Karlsruhe, Germany
  • Ivan Fernandez-Corbaton, Institute of Nanotechnology, Karlsruhe Intitute of Technology (KIT), 76128 Karlsruhe, Germany
We have recently suggested a cavity, defined by two silicon-disk arrays supporting helicity-preserving modes, that allows for enhanced sensing of idealized dual and chiral molecules within the cavity. Here, we simplify this cavity design, aiming at making it robust for experimental realizations. Furthermore, we investigate the influence of the concentration of real chiral molecules, which are usually not dual.
17:00 - 17:15 - Noise-Assisted Sensing with a Nonlinear Optical Resonator Oral [Show abstract]
  • Said Rodriguez, AMOLF, Netherlands
I demonstrate how noise can be turned into a resource for optical sensing when using a resonator with Kerr nonlinearity. The proposed sensor displays a measurement rate that increases monotonically with the noise strength, and a sensitivity that is optimum for a particular value of the noise strength.
17:15 - 17:30 - Hydrogen Sensing Composed of Mg, Ag, Pd nano-blocks by detecting scattering far field pattern distribution Oral [Show abstract]
  • Eunso Shin, Chung-Ang University, Department of Physics, Korea (South)
  • Seung Hyeon Hong, Chung-Ang University, Department of Physics, Korea (South)
  • Young Jin Lee, Chung-Ang University, Department of Physics, Korea (South)
  • Seokhyeon Hong, Chung-Ang University, Department of Physics, Korea (South)
  • Soon-Hong Kwon, Chung-Ang University, Department of Physics, Korea (South)
We proposed an optical hydrogen sensor composed of Mg, Ag and Pd nano-blocks which can detect hydrogen more sensitively compare with conventional methods. This sensor utilizes the properties of Mg and Pd when absorbing hydrogen: metallic Mg becomes dielectric material, MgHx. Pd lattice expands with changing its optical properties. When the material change with hydrogen concentration, the far-field distributions of sensor change significantly at specific scattering angles, 36 and 324 degrees.
17:30 - 17:45 - Permittivity Sensor Based on a Slow-Wave Artificial Transmission Line Oral [Show abstract]
  • Jan Coromina, Universitat Autonoma de Barcelona, Spain
A slow-wave periodic artificial transmission line implemented by means of dumbbell-shaped defect ground structures (DB-DGS) is applied to the implementation of a phase variation permittivity sensor. Due to the dispersion characteristic of these lines, the sensitivity of the phase with the dielectric constant of the material under test (MUT) can be improved, as compared to the one of conventional lines. This sensitivity improvement is demonstrated in this work through full-wave electromagnetic simulations.
17:45 - 18:00 - Differential Microfluidic Sensors based on Electroinductive-Wave (EIW) Transmission Lines Oral [Show abstract]
  • Marta Gil, Universidad Politécnica de Madrid , Spain
  • Paris Velez, Universitat Autonoma de Barcelona, Spain
  • Francisco Aznar-Ballesta, Universidad Politécnica de Madrid , Spain
  • Aran Mesegar-Ruiz, Universidad Politécnica de Madrid , Spain
  • Jonathan Muñoz-Enano, Universitat Autonoma de Barcelona, Spain
  • Ferran Martin, Universitat Autonoma de Barcelona, Spain
We show in this paper that electroinductive-wave (EIW) transmission lines can be applied to the implementation of differential-mode microfluidic sensors with high sensitivity. The sensor is based on EIW lines equipped with microfluidic channels for dielectric characterization of liquid samples. Deionized (DI) water is used as reference (REF) liquid, whereas solutions of isopropanol in DI water are used as liquid under test (LUT).
16:00 - Plasmonics IV

Session chairperson(s): Viktoriia Rutckaia

16:00 - 16:30 - Optical Phase Transitions in Photonic Networks: A Spin System Formulation Invited oral [Show abstract]
  • Tsampikos Kottos, Wesleyan University, USA
  • Alba Ramos, Wesleyan University, USA
  • Lucas Fernandez-Alcazar, Wesleyan University, USA
  • Boris Shapiro, Technion, Israel
Mode mixing due to disorder and non-linear mode coupling dramatically affects the light propagation in multimode systems. Our analysis establishes a connection with the theory of spin networks and reveals the existence of optical phase transitions between a paramagnetic, ferromagnetic and spin-glass phases.
16:30 - 16:45 - Thermal Radiation Engineering via Quantum Nonlinear Mixing of Photons Oral [Show abstract]
  • Chinmay Khandekar, Purdue University , USA
  • Liping Yang , Purdue University, USA
  • Alejandro W. Rodriguez, Princeton University, USA
  • Zubin Jacob, Purdue University, USA
We show that the nonlinear mixing of thermally generated photons in a resonant system can be used to overcome the fundamental blackbody limit on thermal emission, and to introduce nontrivial statistics and biphoton intensity correlations at two distinct frequencies in the emission spectrum. These effects can be observed by heating a properly designed photonic system without using any external signal.
16:45 - 17:00 - Routing Optical Spin and Pseudospin with Metasurfaces Oral [Show abstract]
  • Yarden Mazor, The University of Texas at Austin, USA
  • Andrea Alu, Photonics Initiative, Advanced Science Research Center, City University of New York, USA
Controlling optical spins and pseudospins carried by electromagnetic guided waves can find many applications in the fields of spintronics and valleytronics, supporting efficient information transport using these degrees of freedom. In this work, we explore the general opportunities offered by metasurfaces to route optical momentum, spin and helicity by coupling to guided surface waves. We show how tailoring anisotropy and bianisotropy yields extreme directionality when coupled to the spin of localized sources. In-plane circularly polarized excitations are particularly important in this context when considering 2D excitonic materials. They offer specific challenges when coupled to metasurfaces, addressed here with suitably engineered nonlocality and nonreciprocity.
17:00 - 17:15 - Thermal Spin Photonics In Nonequilibrium And Nonreciprocal Systems Oral [Show abstract]
  • Chinmay Khandekar, Purdue University , USA
  • Zubin Jacob, Purdue University , USA
First, we discover circularly polarized thermal radiation from a dimer of coupled nanoantennas held at unequal temperatures (nonequilibrium). The handedness of light can be flipped by interchanging the antenna temperatures. Second, we reveal that a nonreciprocal planar slab can exhibit nonzero thermal photon spin and heat flux in its vicinity, despite being at thermal equilibrium with the environment.
17:15 - 17:30 - Quantum Effects in the Nonlocal Response of Ultra-Confined Graphene Acoustic Plasmons Oral [Show abstract]
  • Alvaro Rodriguez Echarri, ICFO - The institute of Photonic Sciences, Spain
  • Joel Cox, Center for Nano Optics, University of Southern Denmark, Campusvej 55, DK-5230 Odense M && Danish Institute for Advanced Study, University of Southern Denmark, Campusvej 55, DK-5230 Odense M, Denmark
  • Javier García de Abajo, ICFO - The institute of Photonic Sciences && ICREA – Institució Catalana de Recerca i Estudis Avançats, Passeig Lluís Companys 23, 08010 Barcelona, Spain
We reveal nonlocal and quantum finite-size effects in hybrid systems consisting of graphene and few-atomic-layer noble metals, based on a quantum description that captures the crystallographic orientation of these materials as well as their band structure.
17:30 - 17:45 - Broadband Graphene-Based Metamaterial Solar Absorber Withdrawn [Show abstract]
  • Juveriya Parmar, Marwadi University, India
  • Shobhit Patel, Marwadi University, India
We present broadband metamaterial absorber using split ring resonator and thin wire. The C-shape single split ring resonator and thin wire are placed on a graphene sheet to improve the absorption of the absorber. The thickness of metamaterial and height of substrate material is changed to observe its effect on absorption.
17:45 - 18:00 - Preparation and Patterning of All-Solution Processed MoS2 Precursor with One-Step Annealing without Chemical Vapor Deposition for Atomic 2D Layer Films Withdrawn [Show abstract]
  • Young-Jin Kwack, Hoseo University, Korea (South)
  • Thi Thu Thuy Can, Hoseo University, Korea (South)
  • Woon-Seop Choi, Hoseo University, Korea (South)
The MoS2 precursor solution was formulated by a sulfur-dissolving method. The solution-synthesized MoS2 thin films were controlled to obtain atomic layers without chemical vapor deposition. The precursor solution was applied in an EHD jet printing system to obtain 100 µm patterns, which was used for active layer in TFT applications.
16:00 - Noncreciprocal and topological metamaterials IV

Session chairperson(s): Sander Mann

16:00 - 16:30 - The Effect of Topology to Material Properties: Disordered Hyperuniformity Invited oral [Show abstract]
  • Orestis Christogeorgos, Queen Mary University of London, United Kingdom
  • Qiao Cheng, Queen Mary University of London, United Kingdom
  • Yang Hao, Queen Mary University of London, United Kingdom
The effect of the topology to the properties of a material has been a subject of interest for engineers, physicists and mathematicians around the globe for many years. In particular, the interest is focused towards determining how the arrangement of the fundamental building blocks of a complex system affects its properties. Here, we examine a new state of matter, the so-called hyperuniform disordered, that adopts properties form both the periodic and the random topologies and its effect on several research fields.
16:30 - 16:45 - Sub-Wavelength Passive Optical Isolators Using Weyl Semimetals Oral [Show abstract]
  • Viktar Asadchy, Stanford University, USA
  • Cheng Guo, Stanford University, USA
  • Bo Zhao, Stanford University, USA
  • Shanhui Fan, Stanford University, USA
We design sub-wavelength passive non-reciprocal optical devices using recently discovered magnetic Weyl semimetals. These passive bulk topological materials do not require any external magnetic field and exhibit anomalous Hall effect which results in giant magnetooptical effects. The designed isolators have dimensions that are reduced by three orders of magnitude compared to conventional magneto-optical configurations. Our results indicate that the magnetic Weyl semimetals may open up new avenues in photonics for the design of various nonreciprocal components.
16:45 - 17:00 - Topological Amorphous Metasurfaces Based on Electromagnetic Duality Oral [Show abstract]
  • Dia'aaldin Bisharat, University of California San Diego, USA
  • Dan Sievenpiper, University of California San Diego, United States
In this work, we use electromagnetic-dual metasurfaces to make photonic topological insulators with amorphous and non-periodic patterns. We demonstrate robust pseudospin edge modes at the interface as well as, for the first time, robust localized cavity modes in the interior of the PTI. The newly discovered cavity modes are associated with topological defects in real-space.
17:00 - 17:15 - Highly Efficient and Compact Magnet-Free Isolator Based on Time-Modulated Loops Oral [Show abstract]
  • Sajjad Taravati, University of Toronto, Canada
  • George V. Eleftheriades, University of Toronto, Canada
This study introduces a highly efficient magnet-free isolator based on signal interference in time-modulated loops. The proposed isolator offers strong nonreciprocity. It also possesses a low profile architecture in comparison to other recently proposed space-time-modulated isolators. This is due to the fact that the it is not governed by unidirectional progressive coupling between the input signal and the space-time modulation signal where a long structure is required.
17:15 - 17:30 - 'Perfect' Faraday-Rotation Metasurface Oral [Show abstract]
  • Guillaume Lavigne, Polytechnique Montreal, Canada
  • Toshiro Kodera, Meisei University,, Japan
  • Christophe Caloz, Katholieke Universiteit (KU) Leuven, Belgium
We introduce a ‘perfect’ Faraday-rotation metasurface. This metasurface provides arbitrary-angle, reflectionless and absorptionless nonreciprocal polarization rotation. Moreover,we show, using the surface susceptibility model, that such a metasurface involves a simultaneously electric and magnetic response, which may be realized with transistor-loaded straight and looped wires. This metasurface may potentially accommodate arbitrary incident and refraction angles.
17:30 - 17:45 - Valley-Hall Topological Transport in Graphene Plasmonic Crystal Waveguides Oral [Show abstract]
  • Jian Wei You, University College London, United Kingdom
  • Yupei Wang, University College London, United Kingdom
  • Nicolae Panoiu, University College London, United Kingdom
Due to immunity to disorder and structural imperfections, topologically-protected plasmonic modes have recently attracted increasing attention. Here, we introduce two different mechanisms to construct valley-Hall domain-wall interface waveguides in graphene plasmonic crystal to mimic the quantum valley-Hall effect. In the first case, we break the in-plane spatial inversion symmetry of a single-layer graphene plasmonic crystal waveguide to achieve valley-Hall topological characteristics, whereas in the second case, we break the out-of-plane spatial inversion symmetry of a bi-layer graphene plasmonic crystal waveguide to implement the analog quantum valley-Hall effect. A molecular sensor based on this valley-Hall topological transport phenomenon is also be presented.
17:45 - 18:00 - Topological Bulk Modes for Lasing Application In Kagome Lattice Oral [Show abstract]
  • Stephan Wong, Cardiff University, United Kingdom
  • Sang Soon Oh, Cardiff University, United Kingdom
A photonic topological insulators features waveguiding insensitive to structural imperfections and environmental fluctuations. This has been used to achieve topological insulator lasers based on the waveguide mode and a configuration of gain and loss distribution. Here, we demonstrate a topologically protected mode extended over the bulk of a two-dimensional kagome lattice with rhombus geometry by means of a synthetic imaginary gauge fields via auxiliary rings. This shows a phase-locked broad-area topological lasers in two-dimensional lattices.
16:00 - Analytical and numerical modelling of metastructures IV

Session chairperson(s): Robert Duggan

16:00 - 16:30 - Fundamental Limits to Light–Matter Interactions Invited oral [Show abstract]
  • Owen Miller, Yale University, USA
I discuss recent progress to deriving bounds to electromagnetic response, from single-frequency to broad-band response across near- and far-field scattering regimes. We develop brightness-theorem analogs for wave physics, with ramifications for metasurface design and partially coherent optics. We use quadratic constraints to identify maximum response possible for any material in a given allowable volume. And we identify optimal materials to achieve record levels of near-field radiative heat transfer.
16:30 - 17:00 - Coherent Structures In Dimer Arrays of Nonlinear Circuits Invited oral [Show abstract]
  • Huaiyu Li, Columbia University, USA
  • Michael Weinstein, Columbia University, USA
<p> Coupled arrays of nonlinear circuits with linear inter-cell coupling and nonlinear intra-cell coupling, nonlinear variants of the Su-Schrieffer-Heeger (SSH) model, have been observed to exhibit novel phenomena such as self-induced topologically protected states, see e.g. Hadad et al, ACS Photonics (2017) and Nature Electronics 1 (2018) 178-182. We present an analytical and numerical study of a closely related class of Lagrangian systems. We focus on the regime of excitations whose wavelengths are long compared with the lattice constant, and described by continuum nonlinear partial differential equations. We study (1) the bifurcation of weakly nonlinear coherent structures, such as solitons, from linear regime plane-wave like states, and (2) coherent structures, without amplitude restrictions, by global dynamical systems methods.</p>
17:00 - 17:15 - Sub-Structure Limits to Optical Phenomena Oral [Show abstract]
  • Lukas Jelinek, Czech Technical University in Prague, Czech Republic
  • Mats Gustafsson, Lund University, Sweden
  • Miloslav Capek, Czech Technical University in Prague, Czech Republic
  • Kurt Schab, Santa Clara University, USA
Fundamental limits on scattering metrics such as absorption, extinction, and Purcell's factor are formulated by separating a scattering structure into controllable and uncontrollable regions. We present each bound as a special case of a general methodology based on the method of moments and convex optimization.
17:15 - 17:30 - Boost In Second Harmonic Generation Via Quasi-Bound States In The Continuum in a Gain-Loss Assisted Core-Shelled Nanowire Oral [Show abstract]
  • Harsh K. Gandhi, Indian Institute of Technology Jodhpur, Department of Electrical Engineering, Karwar, 342037, Jodhpur, India, India
  • Davide Rocco, National Institute of Optics (INO), Via Branze 45, 25123, Brescia, Italy, Italy
  • Luca Carletti, University of Padova, Department of Information Engineering, Via G. Gradenigo, 6/A, 35131, Padova, Italy, Italy
  • Costantino De Angelis, University of Brescia, Department of Information Engineering, Via Branze 38, 25123, Brescia, Italy, Italy
Engineering photonic resonators for high-efficiency performance has recently become an avenue for extensive research and development. In this direction, we present that optical Bound states in the continuum can enhance nonlinear response in cavities with spatial variation of gain-loss. We report an enhancement of 3 orders of magnitude in the SHG efficiency in a specially designed AlGaAs nanowire. The formation of high-Q modes via avoided resonance crossing at both the fundamental and second harmonic wavelengths boosts the second harmonic generation (SHG).
17:30 - 17:45 - Spin-mometum Locking of Chiral Surface Waves Oral [Show abstract]
  • Sara Kandil, UC San Diego, USA
  • Dia’aaldin Bisharat, UC San Diego, USA
  • Daniel Sievenpiper, UC San Diego, USA
We introduce a metasurface design that supports chiral surface waves having two transverse spins, one due to out-of-plane field rotation, intrinsic to any surface wave, and the other is due to in-plane field rotation which is imposed by the design. Both spins follow spin-momentum locking resulting in unidirectional wave propagation.
17:45 - 18:00 - Efficient Simulation of Bi-periodic, Layered Structures with the T-Matrix Method Oral [Show abstract]
  • Dominik Beutel, Karlsruhe Institute of Technology (KIT), Germany
  • Achim Groner, Karlsruhe Institute of Technology, Germany
  • Timon Höß, Karlsruhe Institute of Technology, Germany
  • Carsten Rockstuhl, Karlsruhe Institute of Technology, Germany
  • Ivan Fernandez-Corbaton, Karlsruhe Institute of Technology, Germany
We present a combination of T-matrix methods with lattice summation techniques. With this computational method bi-periodic, layered metamaterials can be efficiently simulated. Throughout, we use modes of well-defined helicity as a basis set and, thus, enables the use of chiral materials. Exemplary applications of the method are presented.
2 October 2020 / Start time: 8 h 30 min
08:30 - 09:00 - Closing Ceremony

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