Vector Wave Beams. Changing Polarization of Electromagnetic Wave Beams on Reflection from a Dielectric Plate

We consider electromagnetic vector wave beams and a change in their polarization upon passage through a plane-parallel dielectric plate. A study is based on rigorous solutions of equations for an electromagnetic field.We find the structures of the transmitted and reflected fields. In the case of comparatively narrow beams (with a width of about one wavelength), we determine the reflection coefficients for both normal incidence and incidence at the Brewster angle. __________ Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Radiofizika,Vol. 48, No. 4, pp. 340–349, April 2005.     

Determination of the Phase Shift of a Plasma Wave Reflected from the Edge of a Small-Scale Irregularity

In our papers [1,2], a nonlinear theory has been developed for excitation of plasma-wave eigenmodes inside field-aligned small-radius inhomogeneities in experiments on ionospheric heating by powerful radio waves. This theory takes into account the striction effects of plasma expulsion near the plasma resonance level where a trapped wave is reflected from the edge of the irregularity. The results of this theory depend strongly on the phase of the linear (i.e., weak-field) reflection coefficient. In this paper, we calculate this parameter for irregularities of different shapes.     

Natural Electromagnetic Waves in a Circular Waveguide with a Chiral and a Dielectric Layer

Based on particular solutions of a system of wave equations which describe electromagnetic processes in an unbounded biisotropic medium and are represented in the form of generalized power series, a dispersion equation is obtained for a two-layer circular waveguide with a chiral and a dielectric layer. The solution of the dispersion equation is analyzed for some types of natural waves.     

Tunable Dielectric Properties of Carbon Nanotube@Polypyrrole Core-Shell Hybrids by the Shell Thickness for Electromagnetic Wave Absorption

Carbon nanotube@polypyrrole(CNT@PPy) hybrids have been successfully fabricated via a simple in situ chemical oxidation polymerization. The thickness of the PPy shell can be finely controlled in the range of 3.0–6.4 nm. The dielectric loss of core-shell hybrids can be tuned by the shell thickness, resulting in a well-matched characteristic impedance that can enhance electromagnetic wave(EMW) absorption performance. Minimum reflection loss of the hybrid with moderate PPy shell thickness can reach-51.4 dB at 11.8 GHz with a matching thickness of merely 2 mm. Furthermore, the minimum reflection loss values of the hybrid are below-30 d B even at thickness in the range of 1.4–1.9 mm, endowing the possibility of practical application of the hybrids in electromagnetic wave absorption field.     

Diffraction of a Plane Electromagnetic Wave by an Infinite Double-Ridge Wedge with a Dielectric Cylinder at the Crest

We reduce the considered problem to solving a matrix equation of the second kind for unknown coefficients of expansion of a diffracted field into a Fourier–Bessel series. This expansion was obtained by imposing boundary conditions on the diffracted field with the subsequent re-expansion of the field function over basis functions in a given interval. The expansion coefficients were determined analytically in the case where the electric diameter of the cylinder is less than unity as well as numerically with a high accuracy by solving the obtained matrix equation using the reduction method. We derived expressions for the pattern of the far-zone field scattered by the studied structure and the backscattering cross section and give exact numerical results for the case of an E-polarized incident wave.     

Diffraction of a Plane Electromagnetic Wave by a VO2 Microsphere in the Phase Transition Region

Physics of the Solid State - We present the results of diffraction studies and the electromagnetic (EM) field distribution in a microsphere of vanadium dioxide (VO2) before and after the...     

Spectral Changes of Partially Coherent Light Transmitted from a Dielectric Slab

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Scattering of an Electromagnetic Wave by a Structure Consisting of Several Perfectly Conducting and Dielectric Finite-Length Thin Cylinders

Radiophysics and Quantum Electronics - We generalize a variant of the auxiliary-source method, which was proposed earlier for solving the problem of electromagnetic-wave scattering by a structure...     

介质覆层下金属周期结构变化对TE波异常透射特性的影响

根据金属光栅结构变化对TE波异常透射特性影响的研究需要,建立了相应的模型。应用时域有限差分(FDTD)方法分别计算了单缝结构、多缝结构、不同宽度和不同周期等结构下的透射分布特征。研究发现添加凹槽会对金属表面能量的传递起阻碍作用。透射频域宽度随薄膜宽度增加而增加。随着狭缝宽度的增加,透射率分布曲线包络线趋于平坦,主透射峰短波长侧透射曲线分布基本不变,而主透射峰及其长波长侧的透射曲线分布变宽。这说明宽度的变化影响了表面共振模式,从而影响透射的分布。单个狭缝的透射与多周期结构相比,透射率曲线几乎重合,表明狭缝对表面模式没有调制作用,各狭缝的透射相对独立。     

First-Order Nonspecular Effects Induced by an External Electric Field at the Normal Incidence of a Quasiplane Wave on a Gyrotropic Dielectric Layer

For a ТМ or ТЕ quasiplane wave normally incident on a tangentially magnetized dielectric layer, the application of an external static electric field along the normal to the layer plane results in the appearance of the spatial and angular Goos–Hänchen effects for a beam transmitted through the layer, as well the angular Goos–Hänchen effect for a reflected highly directional wave beam.     

矢量光束界面反射透射的自旋霍耳效应

矢量光束的一般表示方法是利用投影矩阵和广义琼斯矢量的乘积描述.投影矩阵存在一个自由度,该自由度与有限光束的场矢量偏振状态有关,由特定的单位矢量与波矢量间的方位角决定,可以定量地描述矢量光束的偏振状态.本文在矢量光束描述的理论基础上,通过对投影矩阵进行与反射光束与透射光束传播方向相应的坐标旋转,根据麦克斯韦方程组及其边界条件,计算讨论在各向同性介质界面上反射、透射矢量光束的表示形式以及其自旋霍尔效应表现出的横向位移.线偏振光(光子自旋量为σ＝0)横向位移为零,圆偏振光束(光子自旋量为σ＝±1)位移量最大且左圆偏振与右圆偏振光束的位移大小相等方向相反,进一步分析了左圆偏振光束在界面上的反射、透射光束的横向位移与入射角的关系.     

Attenuation of Electromagnetic Waves by a Plasma Layer at Atmospheric Pressure

Plasma layers at atmospheric pressure, are good broad band absorbers of electromagnetic radiation. However, to get substantial attenuations, two parameters have to be optimized. These are the plasma number density, and the thickness of the plasma layer. It is found that in order to be an effective attenuator of microwave radiation, a plasma layer has to have a number density in the 10¹³ cm^–3 range, and a thickness equal or larger than the wavelength of the incident wave. However, as the frequency increases, the amount of attenuation tends to reach a limiting value directly proportional to the number density.     

Diffraction of an Electromagnetic Wave on a Dielectric Rod in a Rectangular Waveguide. A Method of Partial Waveguide Filling

Russian Physics Journal - A variant of the method of partial waveguide filling is considered in which a sample is put into a waveguide through holes in wide waveguide walls at the distance equal to...     

Longitudinal Current Induced by a Plane Electromagnetic Wave in a Single Atom

The change in the polarization state of the atomic response due to the appearence of the longitudinal component, which has been predicted in [A. Andreev, S. Stremoukhov, and O. Shoutova, Europhys. Lett. 120, 14003 (2017)], has been studied. The dependence of the vector properties of the atomic current induced in an atom with unit angular momentum in the ground state on the properties of a two-color laser field with orthogonally polarized components has been analyzed. It has been shown that the variation of the delay time between the frequency components of the laser field makes it possible to efficiently control the polarization of the components of the atomic response field. The effect of the mutual orientation of the electric component of the laser field and the angular momentum of the atom on the longitudinal component of the atomic current and on the polarization properties of the generated radiation has been demonstrated.