A5077910590- Optical Coatings and Gratings
- Photonic Crystals and Applications
- Electromagnetic Scattering and Analysis
- Photonic and Optical Devices
- Metamaterials and Metasurfaces Applications
- Plasmonic and Surface Plasmon Research
- Advanced Antenna and Metasurface Technologies
- Liquid Crystal Research Advancements
- Advanced Fiber Optic Sensors
- Electromagnetic Simulation and Numerical Methods
- Optical Polarization and Ellipsometry
- Near-Field Optical Microscopy
- Orbital Angular Momentum in Optics
- solar cell performance optimization
- Composite Material Mechanics
- Microwave and Dielectric Measurement Techniques
- Acoustic Wave Phenomena Research
- Magneto-Optical Properties and Applications
- Geophysics and Sensor Technology
- Acoustic Wave Resonator Technologies
- Fluid Dynamics and Thin Films
- Thin-Film Transistor Technologies
- Photorefractive and Nonlinear Optics
- Geophysical and Geoelectrical Methods
- Microwave Engineering and Waveguides
Pennsylvania State University
2016-2025
MetaMateria (United States)
2015-2025
University of Edinburgh
2003-2024
Concordia University
2023
Maxwell Institute for Mathematical Sciences
2009-2023
University of Dayton
2023
Technical University of Denmark
2020
Weatherford College
2020
Indian Institute of Technology BHU
2018-2019
Banaras Hindu University
2018-2019
Effective boundary conditions, in the form of two-sided impedance are formulated for linear electrodynamics single- and multishell carbon nanotubes (CN's). The is derived using dynamic conductivity CN's, which obtained different CN's (zigzag, armchair, chiral) frame semiclassical as well quantum-mechanical treatments. Propagation surface waves considered. phase velocities slow-wave coefficients explored a wide frequency range, from microwave to ultraviolet regimes. Relaxation shown...
Abstract A variety of configurations and formats have been devised to exploit the phenomenon surface plasmon on metal dielectric interfaces for sensing a significant analytes, such as pesticides explosives, pathogens toxins, diseased tissue. Researchers continue aim at detecting lower concentrations in smaller volumes samples real time. new research field, called nanoplasmnonics, has emerged this regard.
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Abstract The derivation of a new condition for characterizing isotropic dielectric‐magnetic materials exhibiting negative phase velocity, and the equivalence that with previously derived conditions, are presented. © 2004 Wiley Periodicals, Inc. Microwave Opt Technol Lett 41: 315–316, 2004; Published online in InterScience (www.interscience.wiley.com). DOI 10.1002/mop.20127
The Leontovich-Levin equation for optical scattering by an achiral carbon nanotube (CNT) of finite length is formulated, based on a quantum-mechanical microscopic model the conductivity. Both approximate analytical and numerical solutions yield comparable surface current density distribution pattern. Applications over wide frequency range from terahertz to ultraviolet are possible. CNT polarizability in low-frequency pattern interband transitions as well vicinity plasmon resonance...
Several aspects of electromagnetic wave propagation and scattering in isotropic chiral media (D = ∊E + β∊▽ × E, B μH βμ▽× H) are explored here. All four field vectors, H, D, B, satisfy the same governing differential equation, which reduces to vector Helmholtz equation when β 0. Vector scalar potentials have been postulated. Conservation energy momentum examined. Some properties, consequences, computationally attractive forms applicable infinite-medium Green's function explored. Finally,...
A model for the effective conductivity of a dilute and disordered composite material containing randomly single-wall carbon nanotube (SWCNT) inclusions was formulated. The modification electron transport by surface curvature SWCNTs an axial depolarization effect due to finite length metallic are taken into account. Simultaneous consideration both effects permits correct interpretation dependences on frequency temperature, explains experimentally observed terahertz peak in spectrum conductivity.
Exhibited by structurally chiral materials—such as Reusch piles, cholesteric liquid crystals (CLCs), and sculptured thin films (STFs)—due to their helical nonhomogeneity along a fixed axis, the circular Bragg phenomenon is almost total reflection of incident light co-handed circular-polarization state but very little cross-handed state. Manifesting itself in spectral regimes that depend on angle incidence, structural period, relative permittivity dyadic, amounts formation pipe bleeds energy...
Background and Aims Blue-green iridescence in the tropical rainforest understorey sedge Mapania caudata creates structural coloration its leaves through a novel photonic mechanism.Known structures plants producing iridescent blues consist of altered cellulose layering within cell walls special bodies, thylakoid membranes specialized plastids.This study was undertaken order to determine origin leaf this plant with particular attention nano-scale components contributing coloration.† Methods...
Experimental proof of localized plasmon resonance was found in thin films containing either single-walled carbon nanotubes (SWNT) or SWNT bundles different length. All samples were prepared by a simple technique that permitted the selection lengths without significant differences electronic properties. Fourier-transform infrared spectroscopy showed an optical-density peak, same as terahertz conductivity shifts to higher frequencies are reduced---in agreement with similar tendency predicted...
We study electromagnetic wave propagation in media which the effective relative permittivity and permeability are allowed to take any value upper half of complex plane. A general condition is derived for phase velocity be oppositely directed power flow. That extends recently studied case both simultaneously negative, include dissipation as well. An illustrative demonstrates that spectrum divides into five distinct regions.
We present the technique of bideposition to realize thin-film helicoidal bianisotropic mediums (TFHBM's) that exhibit high optical activity. show, by experiment as well simulation, rotation produced these chiral sculptured thin films is roughly proportional square local linear birefringence. Experimental measurements on bideposited TFHBM's titanium oxide yield a typical value 5 degrees /mum for effective specific in short-wavelength regime; corresponding determined standard unideposited 1...
By controlling the angular relation of substrate surface with respect to incoming vapor direction in an evaporation deposition system, it is possible engineer morphology thin films. Sculptured nematic films result under low adatom mobility conditions when substrates are rotated about axis perpendicular direction. Thin MgF2 were deposited onto room temperature produce columnar morphologies ranging from chevron structures continuously varied resembling S shapes and C shapes. The specific...
Algorithms based on the method of moments (MOM) and coupled dipole (CDM) are commonly used to solve electromagnetic scattering problems. In this paper, strong weak forms both numerical techniques derived for bianisotropic scatterers. The two shown be fully equivalent each other, thereby defusing claims superiority often made charms one technique over other. final section, reductions algorithms isotropic dielectric scatterers explicitly given.
We studied a metasurface constituted as periodic array of semiconductor split-ring resonators. The resonance frequencies the excited by normally incident light were found to be continuously tunable in terahertz regime through an external magnetostatic field suitable orientation. As such metasurfaces can assembled into 3D metamaterials, foregoing conclusion also applies metamaterials comprising
A procedure based on the T-matrix method is devised to study electromagnetic response of chiral, (lossy) dielectric, nonspherical objects exposed an arbitrary incident field. Reductions in for axisymmetric are discussed. Using technique thus developed, plane wave scattering and absorption characteristics lossy scatterers (spheres as well prolate oblate spheroids), with without chiral properties, examined at frequencies above 50 GHz. The relative permittivity assumed be frequency dependent,...