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Related papers: On the active manipulation of EM fields in open wa…

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In this paper we continue to study the feasibility of active manipulation of Helmholtz fields and by using an improved and more robust numerical strategy we present a detailed sensitivity analysis for the method proposed in our previous…

Optimization and Control · Mathematics 2018-10-08 Neil Jerome A. Egarguin , Daniel Onofrei , Eric Platt

This paper investigates the propagation and radiation of spin waves in gyroelectric waveguides within the terahertz (THz) frequency range. With applications in imaging, spectroscopy, and integrated circuits, THz radiation has garnered…

Optics · Physics 2025-03-04 Pushkar Jha

Series expansions of unknown fields $\Phi=\sum\varphi_n Z_n$ in elongated waveguides are commonly used in acoustics, optics, geophysics, water waves and other applications, in the context of coupled-mode theories (CMTs). The transverse…

Numerical Analysis · Mathematics 2017-07-05 Gerassimos A. Athanassoulis , Christos E. Papoutsellis

Diffraction tomography is a noninvasive technique that estimates the refractive indices of unknown objects and involves an inverse-scattering problem governed by the wave equation. Recent works have shown the benefit of nonlinear models of…

Image and Video Processing · Electrical Eng. & Systems 2021-07-09 Tao Hong , Thanh-an Pham , Eran Treister , Michael Unser

We consider a simple model of one-dimensional magnetic crystal and examine the propagation of an electromagnetic wave through such a medium. Calculating the dispersion relation ${\bf k}(\omega)$ allows us to illustrate how the spread of the…

Strongly Correlated Electrons · Physics 2026-05-05 Taras Krokhmalskii , Taras Verkholyak , Ostap Baran , Dmytro Yaremchuk , Taras Hutak , Oleg Derzhko

Terahertz fields can be dramatically enhanced as they propagate through nanometer-sized slits. The enhancement is mediated by significant accumulation of the induced surface charges on the surrounding metal. This enhancement is shown here…

The goal of this work is to study the electromagnetic scattering problem of time-domain Maxwell's equations in an unbounded structure. An exact transparent boundary condition is developed to reformulate the scattering problem into an…

Analysis of PDEs · Mathematics 2016-04-27 Yixian Gao , Peijun Li

We present a ray-based finite element method (ray-FEM) by learning basis adaptive to the underlying high-frequency Helmholtz equation in smooth media. Based on the geometric optics ansatz of the wave field, we learn local dominant ray…

Numerical Analysis · Mathematics 2016-09-01 Jun Fang , Jianliang Qian , Leonardo Zepeda-Núñez , Hongkai Zhao

We suggest the numerical approach to detect eigenfrequencies of trapped modes in waveguides or guided waves in diffraction gratings. At the same time, the approach works perfectly for computation of systems with finitely many scattering…

Quantum Physics · Physics 2007-05-23 Valery E. Grikurov

Flexible manipulation of terahertz-wave polarization during the generation process is very important for terahertz applications, especially for the next-generation on-chip functional terahertz sources. However, current terahertz emitters…

We study an inverse scattering problem for Maxwell's equations in terminating waveguides, where localized reflectors are to be imaged using a remote array of sensors. The array probes the waveguide with waves and measures the scattered…

Numerical Analysis · Mathematics 2015-10-27 Liliana Borcea , Dinh-Liem Nguyen

We present a semianalytical method to obtain perfect transmission across abrupt H-plane bends in single-mode rectangular waveguides using a single passive polarizable element (scatterer). The underlying analysis and synthesis schemes are…

Applied Physics · Physics 2022-04-26 Liran Biniashvili , Ariel Epstein

A Parity Time-reversal Dual (PTD) symmetric structure constituted by a Perfectly-Electric-Perfectly magnetic (PEC-PMC) parallel plate waveguide (PPW) is analyzed. This waveguide supports unimodal transverse electromagnetic (TEM) edge mode…

Classical Physics · Physics 2019-03-27 Enrica Martini , Mario G. Silveirinha , Stefano Maci

We theoretically investigate the dispersion and polarization properties of the electromagnetic waves in a multi-layered structure composed of a magneto-optic waveguide on dielectric substrate covered by one-dimensional dielectric photonic…

Coherent manipulation of magnetism through the lattice provides unprecedented opportunities for controlling spintronic functionalities on the ultrafast timescale. Such nonthermal control conventionally involves nonlinear excitation of…

We introduce a new efficient algorithm for Helmholtz problems in perforated domains with the design of the scheme allowing for possibly large wavenumbers. Our method is based upon the Wavelet-based Edge Multiscale Finite Element Method…

Numerical Analysis · Mathematics 2019-06-21 Shubin Fu , Guanglian Li , Richard Craster , Sebastien Guenneau

We study theoretically antiferromagnet (AFM) based spin-Hall nano-oscillators (SHNOs) consisting of a nano-constriction (NC) in a thin-film uniaxial AFM. By solving the derived SW equation we evidence radially propagating spin waves (SWs)…

Mesoscale and Nanoscale Physics · Physics 2023-08-14 Mohammad Hamdi , Dirk Grundler

We consider the inverse problem for the wave equation on a compact Riemannian manifold or on a bounded domain of $\R^n$, and generalize the concept of {\em domain of influence}. We present an efficient minimization algorithm to compute the…

Analysis of PDEs · Mathematics 2011-01-26 Lauri Oksanen

Consider the elastic scattering of a time-harmonic wave by multiple well separated rigid particles in two dimensions. To avoid using the complex Green's tensor of the elastic wave equation, we utilize the Helmholtz decomposition to convert…

Numerical Analysis · Mathematics 2020-08-17 Jun Lai , Peijun Li

The propagation of free electromagnetic radiation in the field of a plane gravitational wave is investigated. A solution is found one order of approximation beyond the limit of geometrical optics in both transverse--traceless (TT) gauge and…

General Relativity and Quantum Cosmology · Physics 2009-10-31 Enrico Montanari
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