Spectral shifts produced by scattering from rotational quasi-homogeneous anisotropic media

The scattering of the polychromatic plane light wave incident upon rotational quasi-homogeneous anisotropic media is investigated. It is different from the light wave scattered by quasi-homogeneous isotropic medium in that the spectral shift can be produced by the rotation of the anisotropic medium. We derive the analytical formula for the spectrum of the scattered field and show some numerical examples.     

Beam radiated from quasi-homogeneous uniformly polarized electromagnetic source scattering on quasi-homogeneous media

We study the coherence properties of the field generated by beam radiated from quasi-homogeneous (QH) electromagnetic source scattering on QH media. Formulas for the spectral density and spectral degree of coherence of the three dimensional scattered field are derived. The results show under assumption that the diagonal correlation coefficients of the source are proportional to each other, the far field of the scattered light satisfy two reciprocity relations analogous to that in the scalar case, that, the spectral density is proportional to the convolution of the spectral density of the source and the spatial Fourier transform of the correlation coefficient of the scattering potential; the spectral degree of coherence is proportional to the convolution of the diagonal correlation coefficients and the strength of the scattering potential.     

Reciprocity relations for scattering from quasi-homogeneous anisotropic media

Valid within the accuracy of the first-order Born approximation, we obtain the analytical expressions of the three-dimensional spatial Fourier transforms, which show the reciprocity relations for the scattering of a polychromatic plane wave incident upon a Gaussian-correlated, quasi-homogeneous, anisotropic scatterer. We find that the spectral degree of coherence of the scattered field is only related with the effective radius of the scatterer and the normalized spectral density of the scattered field is only related with the correlation length of the scatterer.     

Directive electromagnetic radiation of a line source scattered by a PEMC cylinder coated with anisotropic media

In this paper, the electromagnetic radiation of a line source scattered by an infinite perfect electromagnetic conductor (PEMC) coated with anisotropic media is analytically analyzed. A line source is placed inside the anisotropic media. To validate the presented formulas, the radiation patterns for isotropic cases are compared to the published literature and good agreement is found between them. Also, the directivity of the electromagnetic radiation pattern is improved using the anisotropic coating. Furthermore, when the line source is placed on the surface of PEMC core and the relative tensors of anisotropic shell are appropriately chosen, the co- and cross-polarization components of the fields form the same radiation patterns.     

Momentum transfer from vacuum field to anisotropic electromagnetic media

It is demonstrated that many novel vacuum effects will be caused if an anisotropic electromagnetic environment, which can break the universal symmetry of vacuum, is achieved. It is thus possible for the momentum to be transferred from the vacuum zero-point field to the anisotropic electromagnetic media. In addition to the effect considered by Feigel more recently [A. Feigel, Phys. Rev. Lett. 92 (2004) 020404], there may exist another vacuum-fluctuation contribution to the momentum of a medium. Such an effect has a relativistic origin (resulting from the relativistic transformation of the optical constants), which, however, was not taken into account by Feigel.     

Correlation between intensity fluctuations of light scattered from a quasi-homogeneous random media

The correlation between intensity fluctuations of light scattered from a quasi-homogeneous random media was analytically derived. We showed the correlation depends on spatial Fourier transforms of both the intensity and degree of spatial correlation of scattering potentials of the media, while the normalized correlation equals the squared modulus of the degree of spatial coherence of the scattered fields.     

Coherence and polarization properties in speckle of totally depolarized light scattered by totally depolarizing media

When a totally unpolarized light is scattered by a medium that spatially totally depolarizes incident polarized light, the scattered field presents an increase of the order described by the temporal degree of polarization. We analyze the behavior of some polarization and coherence properties in such a physical situation.     

Beams generated by Gaussian quasi-homogeneous sources

An explicit expression is presented for the cross-spectral density function of the light in any cross-section perpendicular to the axis of a beam generated by a planar, steady-state, quasi-homogeneous source, whose intensity distribution and degree of spatial coherence are both gaussian. The result is used to discuss some properties of such a beam. It is found, in particular, that the ratio of the transvers (spatial) coherence length of the light to the beam width is the same for every cross-section perpendicular to the beam axis.     

The influence of the interface between two media on the structure of the electromagnetic field scattered by a nonlinear half-wave loop

In an approximation of weak nonlinearity, we study experimentally and theoretically the scattering of a plane electromagnetic wave by a ring loop containing a nonlinear local load in the presence of a plane interface between two media. A number of patterns are detected in the structure of the field scattered at higher harmonics, which can be used in the development of nonlinear markers intended for rescue systems.Radiophysical Research Institute, Nizhny Novgorod. Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Radiofizika, Vol. 38, No. 9, pp. 961–968, September, 1995.     

Coherence and polarization properties of a three-dimensional, primary, quasi-homogeneous, and isotropic source and its far field

We study the spatial coherence properties of a three-dimensional, primary, quasi-homogeneous, and isotropic source and the far field that it generates. We assess the spectrum, degree of polarization, electromagnetic degree of coherence, and effective degree of coherence of the source and of the far field. We also demonstrate the formalism for a spherical Gaussian Schell-model current source. The polarization properties of light are fully accounted for in the analysis, and it is found that certain results pertaining to scalar coherence theory are reproduced also within the electromagnetic treatment.     

Generalization of the electromagnetic spinor formalism to anisotropic media

We generalize to magnetically isotropic but electrically anisotropic media the spinor formalism previously developed for isotropic media.     

Propagation of electromagnetic waves generated by moving sources in dispersive media

The propagation of electromagnetic waves issued by modulated moving sources of the form j( t,x ) = a( t )e ^{- iw₀ t} [(x)\dot]₀ ( t )d( x - x₀ ( t ) )j\left( {t,x} \right) = a\left( t \right)e^{ - i\omega _0 t} \dot x_0 \left( t \right)\delta \left( {x - x_0 \left( t \right)} \right) is considered, where j(t, x) stands for the current density vector, x = (x ₁, x ₂, x ₃) ∈ ℝ³ for the space variables, t ∈ ℝ for time, t → x ₀(t) ∈ ℝ³ for the vector function defining the motion of the source, ω ₀ for the eigenfrequency of the source, a(t) for a narrow-band amplitude, and δ for the standard δ function. Suppose that the media under consideration are dispersive. This means that the electric and magnetic permittivity ɛ(ω), μ(ω) depends on the frequency ω. We obtain a representation of electromagnetic fields in the form of time-frequency oscillating integrals whose phase contains a large parameter λ > 0 characterizing the slowness of the change of the amplitude a(t) and the velocity [(x)\dot]₀ ( t )\dot x_0 \left( t \right) and a large distance between positions of the source and the receiver. Applying the two-dimensional stationary phase method to the integrals, we obtain explicit formulas for the electromagnetic field and for the Doppler effects. As an application of our approach, we consider the propagation of electromagnetic waves produced by moving source in a cold nonmagnetized plasma and the Cherenkov radiation in dispersive media.     

Sufficient condition for polarization invariance of beams generated by quasi-homogeneous sources

Conditions for invariance of the degree and the state of polarization of beams radiated by electromagnetic quasi-homogeneous sources into the far-zone are derived. An example is given relating to electromagnetic Bessel-correlated sources.     

Dispersion relation for electromagnetic waves in anisotropic media

Electromagnetic wave propagation in anisotropic dielectric media with two generic matrices εij and μij of permittivity and permeability is studied. In the framework of a metric-free electrodynamics approach, a compact tensorial dispersion relation is derived. The derivation does not require the corresponding matrices to be symmetric, positive definite, nor even invertible. The resulting formula is useful for a theoretical and experimental study of electromagnetic wave propagation in a wide class of linear media.     

Depolarization of the electromagnetic field scattered by a three-dimensional large-scale irregularity of the lower ionosphere

This paper develops analytical and numerical methods for the solution of three-dimensional problems of radio wave propagation. We consider a three-dimensional vector problem for the electromagnetic field of a vertical electric dipole in a planar Earth-ionosphere waveguide with a largescale local irregularity of negative characteristics at the anisotropic ionospheric boundary. The field components at the boundary surfaces obey the Leontovich boundary conditions. The problem is reduced to a system of two-dimensional integral equations taking into account the overexcitation and depolarization of the field scattered by the irregularity. Using asymptotic (with respect to the parameter kr≫1, where r is the distance from the source or receiver to the nearest point of the irregularity, k=2π/λ, and λ is the radio wavelength) integration over the direction perpendicular to the ray path, we transform this system to one-dimensional integral equations where integration contours represent the geometric contour of the irregularity. The system is numerically solved in the diagonal approximation, combining direct inversion of the Volterra integral operator and subsequent iterations. The proposed numerical algorithm reduces the computer time required for the solution of this problem and is applicable for studying both small-scale and large-scale irregularities. We obtained novel estimates for the field components that are not excited by the source but result entirely from scattering by the sample three-dimensional ionospheric irregularity.     

各向异性介质浮雕光栅体内光波场的传输

分析了各向异性介质光栅体内光波场的空间分布,并将RTRA递推算法推向了各向异性介质内光波场的传输.数值计算表明,光波场光强的空间分布随透射深度的变化而变化,各向异性介质光栅体内光波场的空间分布相对各向同性介质要均匀,光栅材料的性质参数和光束的入射参数对光波场光强的空间分布有较大的影响等.     

Coherence and polarization properties of electromagnetic laser modes

A recently formulated mode representation of stochastic electromagnetic fields, based on a unified theory of coherence and polarization is applied to determine the transverse laser resonator modes in any rotationally symmetric cavity. It is found that the electromagnetic modes can be expressed in a simple way in terms of the classic Fox-Li modes of the monochromatic scalar theory; and that, if there is no degeneracy, each mode is completely spatially coherent and its degree of polarization is the same at each point of the cavity mirror.