1k citations · 2k across the 23 of their papers we have counts for
23 papers
Nonreciprocal Local-Resonance Induced Complex Band Hybridization
Wang Tat Yau, Kai Fung Lee, Raymond P. H. Wu +4
We study the complex band hybridization induced by nonreciprocal local resonances in photonic crystals. Composed of trimer unit cells, a two-dimensional (2D) magnetophotonic crysta…
Maxwell's demon-like nonreciprocity by non-Hermitian gyrotropic metasurfaces
Wenyan Wang, Wang Tat Yau, Yanxia Cui +2
We show that Maxwell's demon-like nonreciprocity can be supported in a class of non-Hermitian gyrotropic metasurfaces in the linear regime. The proposed metasurface functions as a…
Topological Theory for Perfect Metasurface Isolators
Wai Chun Wong, Wenyan Wang, Wang Tat Yau +1
We introduce topological theory of perfect isolation: perfect transmission from one side and total reflection from another side simultaneously. The theory provides an efficient app…
Tungsten based Anisotropic Metamaterial as an Ultra-broadband Absorber
Yinyue Lin, Yanxia Cui, Fei Ding +4
The trapped rainbow effect has been mostly found on tapered anisotropic metamaterials (MMs) made of low loss noble metals, such as gold, silver, etc. In this work, we demonstrate t…
Electrical tunability due to coalescence of exceptional points in parity-time symmetric waveguides
Jin Wang, Hui Yuan Dong, Raymond P. H. Wu +2
We demonstrate theoretically the electric tunability due to coalescence of exceptional points in PT-symmetric waveguides bounded by imperfect conductive layers. Owing to the compet…
Anomalous Light Scattering by Topological -symmetric Particle Arrays
C. W. Ling, Ka Hei Choi, T. C. Mok +2
Robust topological edge modes may evolve into complex-frequency modes when a physical system becomes non-Hermitian. We show that, while having negligible forward optical extinction…
Simultaneous Multi-frequency Topological Edge Modes between One-dimensional Photonic Crystals
Ka Hei Choi, C. W. Ling, K. F. Lee +2
We show theoretically that, in the limit of weak dispersion, one-dimensional (1D) binary centrosymmetric photonic crystals can support topological edge modes in all photonic band g…
Chiral plasmon in gapped Dirac systems
Anshuman Kumar, Andrei Nemilentsau, Kin Hung Fung +3
We study the electromagnetic response and surface electromagnetic modes in a generic gapped Dirac material under pumping with circularly polarized light. The valley imbalance due t…
Formation of Non-reciprocal Bands in Magnetized Diatomic Plasmonic Chains
C. W. Ling, Jin Wang, Kin Hung Fung
We show that non-reciprocal bands can be formed in a magnetized periodic chain of spherical plasmonic particles with two particles per unit cell. Simplified form of symmetry operat…
Tunable light-matter interaction and the role of hyperbolicity in graphene-hBN system
Anshuman Kumar, Tony Low, Kin Hung Fung +2
Hexagonal boron nitride (hBN) is a natural hyperbolic material which can also accommodate highly dispersive surface phonon-polariton modes. In this paper, we examine theoretically…
Non-reciprocal mu-near-zero mode in PT-symmetric magnetic domains
Jin Wang, Hui Yuan Dong, Chi Wai Ling +2
We find that a new type of non-reciprocal modes exist at an interface between two \emph{parity-time} () symmetric magnetic domains (MDs) near the frequency of zero ef…
Optical Torque from Enhanced Scattering by Multipolar Plasmonic Resonance
Yoonkyung E. Lee, Kin Hung Fung, Dafei Jin +1
We present a theoretical study of the optical angular momentum transfer from a circularly polarized plane wave to thin metal nanoparticles of different rotational symmetries. While…
Transformation Optics scheme for two-dimensional materials
Anshuman Kumar, Kin Hung Fung, M. T. Homer Reid +1
Two dimensional optical materials, such as graphene can be characterized by a surface conductivity. So far, the transformation optics schemes have focused on three dimensional prop…
Photon Emission Rate Engineering using Graphene Nanodisc Cavities
Anshuman Kumar, Kin Hung Fung, M. T. Homer Reid +1
In this work, we present a systematic study of the plasmon modes in a system of vertically stacked pair of graphene discs. Quasistatic approximation is used to model the eigenmodes…
Super-resolution image transfer by a vortex-like metamaterial
Hui Yuan Dong, Jin Wang, Kin Hung Fung +1
We propose a vortex-like metamaterial device that is capable of transferring image along a spiral route without losing subwavelength information of the image. The super-resolution…
Ferroelectric-Gated Terahertz Plasmonics on Graphene
Dafei Jin, Anshuman Kumar, Kin Hung Fung +2
Inspired by recent advancement of low-power ferroelectic-gated memories and transistors, we propose a design of ferroelectic-gated nanoplasmonic devices based on graphene sheets cl…
Electron-photon scattering mediated by localized plasmons: A quantitative analysis by eigen-response theory
Kin Hung Fung, Anil Kumar, Nicholas X. Fang
We show that the scattering interaction between a high energy electron and a photon can be strongly enhanced by different types of localized plasmons in a non-trivial way. The scat…
Ultra-broadband Light Absorption by a Sawtooth Anisotropic Metamaterial Slab
Yanxia Cui, Kin Hung Fung, Jun Xu +4
We present an ultra broadband thin-film infrared absorber made of saw-toothed anisotropic metamaterial. Absorbtivity of higher than 95% at normal incidence is supported in a wide r…
A Thin Film Broadband Absorber Based on Multi-sized Nanoantennas
Yanxia Cui, Jun Xu, Kin Hung Fung +4
We experimentally demonstrate an infrared broadband absorber for TM polarized light based on an array of nanostrip antennas of several different sizes. The broadband property is du…
Zeeman Splitting of Photonic Angular Momentum States in Gyromagnetic Cylinder
Kin Hung Fung, Jin Wang, Hui Yuan Dong +1
We show that under the presence of a static magnetic field the photon eigen-frequencies of a circular gyromagnetic cylinder experience a splitting that is proportional to the angul…
Excitation and Imaging of Resonant Optical Modes of Au Triangular Nano-Antennas Using Cathodoluminescence Spectroscopy
Anil Kumar, Kin-Hung Fung, James C. Mabon +2
Cathodoluminescence (CL) imaging spectroscopy is an important technique to understand resonant behavior of optical nanoantennas. We report high-resolution CL spectroscopy of triang…
Thin Film Absorbers Based on Plasmonic Phase Resonances
Yanxia Cui, Kin Hung Fung, Jun Xu +2
We demonstrate an efficient double-layer light absorber by exciting plasmonic phase resonances. We show that the addition of grooves can cause mode splitting of the plasmonic waveg…
Imaging of plasmonic modes of silver nanoparticles using high-resolution cathodoluminescence spectroscopy
Pratik Chaturvedi, Keng Hsu, Anil Kumar +2
Cathodoluminescence spectroscopy has been performed on silver nanoparticles in a scanning electron microscopy setup. Peaks appearing in the visible range for particles fabricated o…