Propagation Of Electromagnetic Plane Waves Research Articles

Modelling the propagation of electromagnetic plane waves in lossless, nonmagnetic multilayer thin films using polynomial model

Modelling the propagation of electromagnetic plane waves in lossless, nonmagnetic multilayer thin films using polynomial model

Loss-gain compensated anti-Hermitian magnetodielectric medium to realize Tellegen nihility effects.

Generalized duality transformations significantly modify the constitutive relations of electromagnetic media, preserving principal electromagnetic properties. Here, we contemplate transformation of Tellegen nihility as a specific type of extreme-property nonreciprocal bi-isotropic media and show that some intriguing electromagnetic properties of that medium can be realized in a particular class of isotropic magnetodielectric media without magnetoelectric coupling. We show that the permittivity and permeability of the corresponding transformed medium have equal absolute values and opposite signs. Depending on the value of the Tellegen parameter of the original medium, the transformed magnetodielectric medium can be Hermitian, non-Hermitian, or anti-Hermitian, which simultaneously exhibits loss and gain. Focusing on the latter class of anti-Hermitian media, we theoretically and numerically demonstrate that this extraordinary medium allows propagation of electromagnetic plane waves having zero time-averaged Poynting vector, similarly to the original Tellegen nihility media. Hopefully, this work can open novel opportunities for manipulating electromagnetic fields.

ANIMATION OF PLANE ELECTROMAGNETIC WAVES IN VACUUM USING WINPLOT SOFTWARE

In this work, the Winplot software was used to animate plane electromagnetic waves in a vacuum. The target audience was a class of 18 undergraduates in Physics and was applied at the Federal University of Acre, campus Rio Branco, in Brazil. The activity was carried out in a computer lab and conducted through a script with detailed instructions. The results were satisfactory, where participants got more than 60.0% right of four of the six investigative questions. In evaluating the activity, 88.9% considered it a good method to visualize the propagation of electromagnetic waves and 77.0% classified the activity as excellent or good. The application of the activity allowed a dynamic view of the propagation of plane electromagnetic waves in a vacuum, which could contribute to the teaching of such content.

Pedagogical tool to teach electromagnetic plane wave propagation in various media environments

In the usual process of teaching students about the electromagnetic field, students often have difficulty in understanding the propagation process of invisible electromagnetic waves under different medium environments. To facilitate students understanding and learning of related knowledge, in this article, we first derive the process of solving Maxwell’s equation using finite-difference time-domain (FDTD) under different media environments for the designed experimental models to obtain the spatial distribution of the electromagnetic field. After that, we use the MATLAB language to program the FDTD solution method to verify our theoretical analysis based on the simulation results. Based on this, we develop a convenient and quick interactive mobile software tool, aiming to give students a vivid and intuitive demonstration and explanation for the propagation of electromagnetic waves in different media environments.

Plane electromagnetic wave propagation of pulsed periodic field in conductive half-space

Nowadays, application of pulsed periodic fields in various technological devices is of interest, in particular for the influencing on a conductive media. In this paper solution of the problem of the propagation of a plane electromagnetic wave of pulsed periodic field created by a planar inductor, in the conductive half-space is presented. The solution is obtained in the form of Fourier series as a function of a complex argument. The differential and integral characteristics of the “inductor-conductive half-space” system for different values of the inductor time constant are determined. A comparative analysis of the obtained results with the electromagnetic characteristics of plane sinusoidal electromagnetic wave propagation process in conductive half-space is made.

Negative refraction of plane electromagnetic waves in non-uniform double-negative media.

We propose a new model of a plane-layered medium with a fixed positive refractive index, but variable non-vanishing dielectric permittivity and magnetic permeability. An analytical solution of the problem of plane electromagnetic wave propagation through the medium has been found. It is shown that the negative-refraction effect occurs in this type of medium; in particular, an explicit expression for the field has been first obtained in the region of its formation. This result suggests that the necessary condition for the occurrence of this effect in quite complex media is not the negativity of their refractive indices, but only the requirement of simultaneous negativity of the real parts of dielectric permittivity and magnetic permeability. We also demonstrate that the medium is passive (absorbing) if a plane E-polarized wave propagates in it, and active (amplifying) in the case of H-polarized wave propagation.

Three-dimensional electrodynamic code ELF

The paper is devoted to the description of the three-dimensional ELF code developed in RFNC-VNIITF. This code is intended to simulate the problems of electrodynamics, plasma physics, acceleration of electrons and ions on laser and electrophysical facilities. The code is based on solving the Vlasov kinetic equation and the Maxwell equations system. To solve the Vlasov equations, the method of particles in cells is used. An explicitly finite difference scheme of the second order of accuracy is used to solve the Maxwell equations. A set of analytical tests (propagation of plane electromagnetic wave in plasma, motion of an electron in electric and magnetic fields, etc.) is given and a good agreement of the numerical solution with them is shown. The order of convergence of the numerical algorithms also determined. The calculations of the accelerated electrons in plasma wakefield are presented, and the results of comparison with experiment for the parameters for the laser facility of RFNC-VNIITF are demonstrated.

Low reflection and high transmission by a layered structure containing diamond-like carbon, porous silicon, and left-handed material

In this paper, we propose and theoretically analyze a stratified waveguide structure comprised of diamond-like carbon (DLC), porous silicon (PS), and left-handed material (LHM) subjected to incident light in order to achieve low reflection and high transmission. The proposed waveguide structure is situated between two half free spaces and a TE polarized plane wave incident on it. The main parameters of each material are given and the required equations for the electromagnetic plane wave propagation are presented. Transfer matrix method is implemented to find out the characteristics of the reflected and transmitted powers. In the numerical results, the mentioned powers are computed and illustrated as a function of the incidence angle, the frequency, and the slab thickness to demonstrate the main parameters for low reflection and high transmission. These theoretical parameters could be useful to the researchers and designers working in the area of solar cells and optical sensors.

Elliptically polarized breather in the nonintegrable problem of laser radiation propagation through an isotropic gyrotropic nonlinear medium

A particular analytical solution to the nonintegrable problem of plane electromagnetic wave propagation through an isotropic gyrotropic nonlinear medium is found in the form of elliptically polarized breather. The intensity ratio for the circularly polarized components of this wave, which remains constant during propagation, can be used to determine the ratio of local and nonlocal nonlinear susceptibilities describing the Kerr nonlinearity and its spatial dispersion.

Numerical study of antireflection coatings in waveguide structures with silicon nanoparticles interlayer

In this paper, the reflection properties of a multilayer structure containing silicon nanoparticles (Si-NPs), silicon nitride (Si3N4), and silicon (Si) is investigated theoretically and numerically. The structure is arranged and its main parameters are defined. The required equations for the propagation of electromagnetic plane waves are derived in detail to obtain the reflection coefficients in a closed form. The reflected power of the structure is determined using these coefficients. In the numerical results, the mentioned power is computed and illustrated as a function of wavelength of the incident radiation, angle of incidence, and Si-NPs parameters. Optimal Si-NPs parameters (particle’s diameter, space between particles, and layer thickness) for low reflection are proposed. These theoretical parameters could effectively be used to design new solar cells.

Fabrication of sub-wavelength antireflective structure to enhance the efficiency of InGaAs solar cells

Large differences in the refractive index between semiconductors (Si, GaAs, etc.) and air produces considerable Fresnel loss, which can seriously hinder the absorption of sunlight by photovoltaic solar cells. This study presents a cost-effective roller nanoimprinting technique for the fabrication of sub-wavelength structures (SWSs) as an alternative to conventional anti-reflective coatings used to reduce reflectance in triple-junction InGaP/InGaAs/Ge solar cells. The proposed nanoimprinting technology uses a soft PDMS mold duplicated from a hard silicon template, which is fabricated using PS sphere lithography and dry etching processes. To evaluate the anti-reflective performance of SWSs, we employed rigorous coupled wave analysis (RCWA) to simulate the propagation of electromagnetic plane waves in a GaAs substrate. Simulation results demonstrated a considerable reduction in reflectance resulting from a gradual change in the refractive index provided by SWSs. Photoelectric conversion efficiency was also increased.

Optimization of electromagnetic wave propagation through a liquid crystal layer

We study the propagation of electromagnetic plane waves through a liquid crystal layer paying particular attention to the problem of optimizing the transmitted intensity. The controllable anisotropy of a liquid crystal layer, either through anchoring conditions on supporting glass plates sandwiching the layer or by the imposition of an external electromagnetic field, allows us to tune the orientation of the layer to maximize or minimize the transmitted intensity of a given wavelength through the layer. For a homogeneous liquid crystal orientation field, we find analytical formulas for the orientation that maximizes the transmission and discuss the circumstances under which we can make the layer effectively transparent for a given wavelength and the possibility of multiple maximizing orientations. The minimizing orientation is unique for a given wavelength, and we can define its value implicitly.

Electromagnetic waves in the gravitational field of massive dark halos

The propagation of plane electromagnetic waves in the gravitational field inside a rotating cloud of dark matter is analyzed. Formulas for the deflection and absorption of light, and the rotation of the polarization plane are obtained in closed form in terms of the mass density and the angular velocity of the cloud. It is shown that the formulas can be considerably simplified for axisymmetric configurations. As an example, the formalism is applied to a rotating massive cloud described by a Plummer potential.

GPR determination of physical parameters of railway structural layers

Abstract The paper studies the possibility of quantitative processing of the GPR data for determining the refractive index and conductivity of motor road and railway constructional layers. The main objective of the work is to develop a method of obtaining quantitative information on chosen physical properties of soil layers from regular GPR surveys. Theoretical study of plane electromagnetic wave propagation is made for the model of layered soil structure. As a result of the study appropriate equation systems are derived for the calculations of refractive index and conductivity of structural layers. Based on these equations the method of quantitative processing of radargrams is proposed. The method includes the GPR data processing algorithm and theoretical techniques for determination of refractive index and conductivity of the structural layers. The applicability of the proposed method was initially validated by lab experiments using radargrams of the soil samples with specified values of moisture and conductivity and reliable results were achieved. The methods were also successfully used while monitoring the long term seasonal changes in structural layers of several Russian railways sections. The contamination of ballast material is also evaluated by this method in addition to the refractive index and conductivity.

Light interaction with multilayer arbitrary anisotropic structure: an explicit analytical solution and application for subwavelength imaging

A systematic analytical approach to simulate the propagation of electromagnetic plane waves in multilayer anisotropic structures, where the layers can have arbitrary oriented optical axis, is presented. The explicit expressions for the vector polarizations of electric and magnetic fields inside a randomly oriented anisotropic medium are derived. The developed algorithm operates with analytic 4×4 matrices to calculate the transmission and reflection coefficients. This algorithm is suitable to investigate the near-field/far-field electromagnetic wave interaction at any angle of incidence for numerous intriguing applications. The procedure is applied to design anisotropic single and multilayer lenses for subwavelength imaging.

An improved model for nanosecond pulsed laser ablation of metals

A model is presented for the ablation of metals by nanosecond laser pulses, based on one-dimensional heat flow with temperature dependent material properties. A numerical optical calculation is introduced to account for laser beam absorption in the target, utilizing established matrix methods for electromagnetic plane wave propagation in multi-layered media. By including the effects of reflection from the dielectric-metal interface, the fall in reflectivity of aluminum during nanosecond laser pulses above the phase explosion threshold is found to be approximately twice that calculated in previous works. A simulated shielding coefficient is introduced to account for reflection and absorption of the incident laser beam by the ablation products. With these additions to foregoing models, good agreement between calculated and published experimental ablation data is attained for aluminum, both in terms of ablation threshold and depth. An investigation is subsequently carried out into the effects of laser wavelength, pulse duration and target thickness on the phase explosion threshold of aluminum.

Electromagnetic wave propagation in (bianisotropic) magnetoelectric materials

The propagation of electromagnetic plane waves in linear magnetoelectric materials is studied. The wave equation is derived as a generalized two-dimensional eigenvalue problem, and a method of calculating the propagating wave modes is presented. An analytic dispersion relation for general bianisotropic materials is given. Additionally, an analytic model is presented, which decomposes electric and magnetic fields into coupled and uncoupled components. This model provides a methodology for characterizing the coupled field parameters in terms of the polarizations induced by cross-coupling effects in magnetoelectric materials. From this formulation, the interactions of applied fields in magnetoelectric materials are contrasted with conventional material counterparts. This is then used to characterize the fields in terms of polarizations induced by the uncoupled components and cross-coupling parameters. Reciprocal and nonreciprocal configurations of magnetoelectric materials are identified. The similarities and differences of nonreciprocal magnetoelectric materials to Faraday materials are described. Directional dependence of the propagating modes is shown graphically and described.

Electromagnetic wave propagation with negative phase velocity in regular black holes

We discuss the propagation of electromagnetic plane waves with negative phase velocity in regular black holes. For this purpose, we consider the Bardeen model as a nonlinear magnetic monopole and the Bardeen model coupled to nonlinear electrodynamics with a cosmological constant. It turns out that the region outside the event horizon of each regular black hole does not support negative phase velocity propagation, while its possibility in the region inside the event horizon is discussed.

Wave Propagation in Nanodoped Films

We analyze the propagation of electromagnetic plane waves through a dielectric film endo-wed with a nano doped permittivity made of a sequence of Dirac delta pulses.

Reflection and Propagation of Electromagnetic Wave in Time-varying Medium

The reflection of plane electromagnetic wave on the interface between time-varying medium and time-invariant medium and the propagation of plane electromagnetic wave in time-varying medium are studied in this article. The medium which changes with time as an exponential function is observed and the analytical solution of the electromagnetic wave in such medium is obtained by the method of separation variables. The transient reflection coefficient on the surface of the time-varying medium and the transient transmission coefficient in time-varying medium are obtained for the first time by taking the limit for time increment. The validity of the solution is testified by three approaches. The propagation characteristics are discussed by the example in different areas.