Explicit Solution of the Time Domain Volume Integral Equation Using a Stable Predictor-Corrector Scheme

An explicit marching-on-in-time (MOT) scheme for solving the time domain volume integral equation is presented. The proposed method achieves its stability by employing, at each time step, a corrector scheme, which updates/corrects fields computed by the explicit predictor scheme. The proposedmethod is computationally more efficient when compared to the existing filtering techniques used for the stabilization of explicit MOT schemes. Numerical results presented in this paper demonstrate that the proposed method maintains its stability even when applied to the analysis of electromagnetic wave interactions with electrically large structures meshed using approximately half a million discretization elements

Nonlinear acousto-magneto-plasmonics

We review the recent progress in experimental and theoretical research of interactions between the acoustic, magnetic and plasmonic transients in hybrid metal-ferromagnet multilayer structures excited by ultrashort laser pulses. The main focus is on understanding the nonlinear aspects of the acoustic dynamics in materials as well as the peculiarities in the nonlinear optical and magneto-optical response. For example, the nonlinear optical detection is illustrated in details by probing the static magneto-optical second harmonic generation in gold-cobalt-silver trilayer structures in Kretschmann geometry. Furthermore, we show experimentally how the nonlinear reshaping of giant ultrashort acoustic pulses propagating in gold can be quantified by time-resolved plasmonic interferometry and how these ultrashort optical pulses dynamically modulate the optical nonlinearities. The effective medium approximation for the optical properties of hybrid multilayers facilitates the understanding of novel optical detection techniques. In the discussion we highlight recent works on the nonlinear magneto-elastic interactions, and strain-induced effects in semiconductor quantum dots.Comment: 30 pages, 12 figures, to be published as a Topical Review in the Journal of Optic

Experimental Study of the Superconducting Microstrip Antenna as a Protective Device of the Receiver From Electromagnetic Damage

The paper presents the results of experimental studies of a superconducting protective antenna, which consists of a high-temperature film deposited by a magnetron or a laser beam on a substrate. The work is carried out:- analysis of the selection criteria for the substrate type (Al2O3, Y2O3, SrTiO3, MgO) and the method for depositing a high-temperature superconducting film (HTSF) on its surface – YBaCuO- analysis of the methods of making contacts, which allow to reduce losses when passing a signal from the superconducting microstrip antenna to the waveguide path.The aim of this article is determination of the parameters of a prototype sample of a microstrip antenna device made from HTSF: transient characteristics of high-temperature superconductors, HTSF impulsive characteristics, recovery time of the superconducting state after the action of a powerful pulse on the protective device, the amplitude-frequency characteristics of the protective device in the superconducting state. This will allow to evaluate the possibility of using a microstrip antenna device made from high-temperature superconductors to protect the receiving systems from electromagnetic damage. The absence of a unified theory of high-temperature superconductivity leads to the need to select an analytical form of the functions of the amplitude-frequency characteristics of superconducting protection, and for this mathematical models are used in the programs "APPROX", "MathCAD14.0". The reliability of the obtained results of mathematical modeling of the processes of protection and recovery of the superconducting state after electromagnetic shock are confirmed in the course of experimental studies (an error of 0.15%)

Electromagnetic Pulse of a Vertical Electric Dipole in the Presence of Three-Layered Region

Approximate formulas are obtained for the electromagnetic pulses due to a delta-function current in a vertical electric dipole on the planar surface of a perfect conductor coated by a dielectric layer. The new approximated formulas for the electromagnetic field in time domain are retreated analytically and some new results are obtained. Computations and discussions are carried out for the time-domain field components radiated by a vertical electric dipole in the presence of three-layered region. It is shown that the trapped-surface-wave terms should be included in the total transient field when both the vertical electric dipole and the observation point are on or near the planar surface of the dielectric-coated earth

Photonic Localization of Interface Modes at the Boundary between Metal and Fibonacci Quasi-Periodic Structure

We investigated on the interface modes in a heterostructure consisting of a semi-infinite metallic layer and a semi-infinite Fibonacci quasi-periodic structure. Various properties of the interface modes, such as their spatial localizations, self-similarities, and multifractal properties are studied. The interface modes decay exponentially in different ways and the modes in the lower stable gap possess highest spatial localization. A localization index is introduced to understand the localization properties of the interface modes. We found that the localization index of the interface modes in the upper stable gap will converge to two slightly different constants according to the parity of the Fibonacci generation. In addition, the localization-delocalization transition is also found in the interface modes of the transient gap.Comment: 20 pages, 5figure

Properties of Physical Systems: Transient Singularities on Borders and Surface Transitive Zones

Certain alternative properties of physical systems are describable by supports of arguments of response functions (e.g. light cone, borders of media) and expressed by projectors; corresponding equations of restraints lead to dispersion relations, theorems of counting, etc. As supports are measurable, their absolutely strict borders contradict the spirit of quantum theory and their quantum evolution leading to appearance of subtractions or certain needed flattening would be considered. Flattening of projectors introduce transitive zones that can be examined as a specification of adiabatic hypothesis or the Bogoliubov regulatory function in QED. For demonstration of their possibilities the phenomena of refraction and reflection of electromagnetic wave are considered; they show, in particular, the inevitable appearing of double electromagnetic layers on all surfaces that formerly were repeatedly postulated, etc. Quantum dynamics of projectors proves the neediness of subtractions that usually are artificially adding and express transient singularities and zones in squeezed forms.Comment: 12 p

Application of coupled-wave Wentzel-Kramers-Brillouin approximation to ground penetrating radar

This paper deals with bistatic subsurface probing of a horizontally layered dielectric half-space by means of ultra-wideband electromagnetic waves. In particular, the main objective of this work is to present a new method for the solution of the two-dimensional back-scattering problem arising when a pulsed electromagnetic signal impinges on a non-uniform dielectric half-space; this scenario is of interest for ground penetrating radar (GPR) applications. For the analytical description of the signal generated by the interaction of the emitted pulse with the environment, we developed and implemented a novel time-domain version of the coupled-wave Wentzel-Kramers-Brillouin approximation. We compared our solution with finite-difference time-domain (FDTD) results, achieving a very good agreement. We then applied the proposed technique to two case studies: in particular, our method was employed for the post-processing of experimental radargrams collected on Lake Chebarkul, in Russia, and for the simulation of GPR probing of the Moon surface, to detect smooth gradients of the dielectric permittivity in lunar regolith. The main conclusions resulting from our study are that our semi-analytical method is accurate, radically accelerates calculations compared to simpler mathematical formulations with a mostly numerical nature (such as the FDTD technique), and can be effectively used to aid the interpretation of GPR data. The method is capable to correctly predict the protracted return signals originated by smooth transition layers of the subsurface dielectric medium. The accuracy and numerical efficiency of our computational approach make promising its further development