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1.
There are both loss and dispersion characteristics for most
dielectric media. In quantum theory the loss in medium is generally
described by Langevin force in the Langevin noise (LN) scheme by
which the quantization of the radiation field in various homogeneous
absorbing dielectrics can be successfully actualized. However, it is
invalid for the anisotropic dispersion medium. This paper extends
the LN theory to an anisotropic dispersion medium and presented the
quantization of the radiation field as well as the transformation
relation between the homogeneous and anisotropic dispersion media. 相似文献
2.
Analytical expressions of electric fields inside and outside an
anisotropic dielectric sphere are presented by transforming
an anisotropic medium into an isotropic one based on the multi-scale
transformation of electromagnetic theory. The theoretical
expressions are consistent with those in the literature. The inside
electric field, the outside electric field and the angle between
their directions are derived in detail. Numerical simulations show
that the direction of the outside field influences the magnitude of the
inside field, while the dielectric constant tensor greatly affects
its direction. 相似文献
3.
Maxwell’s equations are considered for waves in transparent inhomogeneous anisotropic and gyrotropic media with time dispersion.
A uniaxial inhomogeneous crystal is taken for an anisotropic medium and an isotropic heterogeneous medium in a constant electric
field for a gyrotropic medium. The solutions for flat-layered and cylindrical media are presented in terms of Hertz potentials.
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Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 3, pp. 82–86, March, 2008. 相似文献
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G. Stojmenovik S. Vermael F. Beunis K. Neyts A. R. M. Verschueren 《Opto-Electronics Review》2007,15(1):13-19
A new Monte Carlo algorithm for ion transport in two-dimensional anisotropic media is reported. It is based on physical considerations
of drift and diffusion in anisotropic media with or without an impermeable boundary. Inhomogeneities in the medium and electric
field can be taken into account by averaging along the ion trajectory. The algorithm has been applied to the calculation of
ion transport in liquid crystal displays and has been successfully compared with a finite difference program on a one-dimensional
liquid crystal structure. 相似文献
6.
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. 相似文献
7.
A nonstationary problem of the thermal conductivity of cylindrical tubes is considered for the case when there is a medium inside the tube which has an anisotropic thermal conductivity.The problem is solved for very general initial and boundary conditions which enables problems of a similar nature in this field to be solved. 相似文献
8.
The energy losses of fast charged particles in anisotropic media are investigated. The macroscopic Maxwell equations are used to find the electromagnetic field of particles moving according to a given law in an anisotropic medium. A solution in quadratures is obtained for the energy loss of a charge moving at an angle to the optical axis of a weakly anisotropic uniaxial crystal; the result is in the form of a correction to the ionization losses in an isotropic medium. In the case of a medium consisting of anisotropic oscillators, an analytic formula is obtained for the correction: It is inversely proportional to the square of the velocity at particle velocities much less than the velocity of light and tends to zero for ultrarelativistic particles.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 1, pp. 14–19, January, 1978.Finally, it remains to thank O. B. Evdokimov for formulating the problem and for useful discussions. 相似文献
9.
It is shown that the state of a thermoelectric medium can be described by a single mathematical object — a generating function for a thermoelectric field. The relation between the generating function and the vector potential of the current density, the temperature distribution, and the potentials for uniform anisotropic and nonuniform isotropic media are considered.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fiziki, No. 5, pp. 21–24, May, 1986. 相似文献
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We analyzed features of the influence of perturbations in an anisotropic medium on the propagation of quasioptical wave beams.
The solutions of the quasioptical equation in the nonaberrational approximation are found, which describe the evolution of
the wave-beam width. It is shown that the influence of perturbations in an anisotropic medium differs qualitatively from the
influence of the perturbations in an isotropic medium. Examples are presented of numerical calculations of the wave beam profiles
in model media corresponding to the cases of density and magnetic field perturbations in the magnetoplasma confined in toroidal
devices (tokamaks and stellarators). 相似文献
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Zhichao Wang Qiang Cheng Guihua Wang Huaichun Zhou 《Journal of Quantitative Spectroscopy & Radiative Transfer》2011,112(18):2835-2845
This paper extends the DRESOR (Distribution of Ratios of Energy Scattered by the medium Or Reflected by the boundary surface) method to radiative transfer in a variable refractive index medium. In this method, the intensity is obtained from the source term along the curved integration paths determined only by the variable refractive index, and the DRESOR values are calculated by the Monte Carlo method in which the propagation of the energy bundles are affected by Snell's law. With given temperatures on the black boundaries of a one-dimensional medium, the temperature distribution inside the medium with a variable scattering property is calculated under the condition of radiative equilibrium. It is shown that the DRESOR method has a good accuracy in the cases studied. For an isotropic-scattering medium with the same optical thickness, the scattering albedo has no effect on the temperature distribution, which can be obtained from the general equations and can be seen as an extension of what exists for a constant refractive index; however, the different refractive index causes obvious changes in the temperatures inside the medium. The effect of anisotropic scattering on the temperature distribution cannot be ignored, although it is still weaker than the effect caused by variation in the refractive index. 相似文献
14.
By invoking ideas about the distribution of the optical paths of partial components of the scattered field, we obtain an expression for estimating the degree of residual polarization of light that is incoherently backscattered from a disordered multiply scattering semi-infinite medium illuminated by linearly polarized light. In the backscattering regime, the depolarization length of the linearly polarized light in the disordered medium becomes smaller with the passage from the isotropic to anisotropic scattering. Experiments with model media featuring substantially anisotropic scattering (the anisotropy parameter of 0.90 ≤ g ≤ 0.95) demonstrated that for backscattering of linearly polarized light, the depolarization length is close to the transport length of the scattering medium. 相似文献
15.
We consider a generalization of the effective medium approximation to the case of matrices containing macroscopically inhomogeneous particles with an arbitrary structure (cermet topology). The form of the result is determined to a considerable extent by the heuristic choice of effective cells used to estimate the field and induction values averaged over the volume. The simplest choice of a particle in an unperturbed field as a cell leads to the Maxwell–Garnett approximation, while the self-consistent effective medium approximation corresponds to the replacement of the unperturbed field by the mean field. As an example, we describe particles with a shell, as well as statistically anisotropic media with a single preferred direction. 相似文献
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基于位函数的引入与介质参量无关,将各向异性目标内外的电场展为级数形式,得到了任意各向异性目标n阶散射场、目标内场的递推表达式,给出了介电常量张量的变换关系,在平面波任意入射的条件下,并给出了传播单位矢量与极化单位矢量的一般关系.以磁化冷等离子体为例,给出了一阶散射场的具体表达式,并对二阶散射场引起的误差进行了评估.在THz波段和光波段,对所得结果进行了部分仿真.结果表明:微分散射对电波频率和极化状态等因素的影响较为敏感,介电常量张量的非对角元素对散射的影响不大,当波长与目标尺寸一定时,仿真结果不仅适用于THz波段,对其它波段也成立. 相似文献
18.
G. Macheleidt 《Annalen der Physik》1980,492(3):200-212
Green's Function of Optically Anisotropic Media The time-fouriertransformed dyadic Green's function is calculated in the far-field-approximation for optically anisotropic media. To this end the time- and space-fouriertransformed Green's tensor-function is represented by dyadic products of the eigenvectors of the homogeneous Fresnel's equation, and the transformation back into space is done in the asymptotic limit by the stationary phase integration method. As an application the radiation field of an electric dipole in an optically anisotropic medium is evaluated. All results are discussed in the case of uniaxial crystals. 相似文献
19.
基于位函数的引入与介质参量无关,将各向异性目标内外的电场展为级数形式,得到了任意各向异性目标n阶散射场、目标内场的递推表达式,给出了介电常量张量的变换关系,在平面波任意入射的条件下,并给出了传播单位矢量与极化单位矢量的一般关系.以磁化冷等离子体为例,给出了一阶散射场的具体表达式,并对二阶散射场引起的误差进行了评估.在THz波段和光波段,对所得结果进行了部分仿真.结果表明:微分散射对电波频率和极化状态等因素的影响较为敏感,介电常量张量的非对角元素对散射的影响不大,当波长与目标尺寸一定时,仿真结果不仅适用于THz波段,对其它波段也成立. 相似文献
20.
We present a theoretical and experimental investigation of Bragg scattering of surface magnetostatic waves (SMSW) by a time-independent, spatially periodic magnetic field when the wave orientation is arbitrary with respect to the magnetization field. In the theoretical section the theory of single-mode Bragg diffraction is generalized to the case of waves with arbitrary dispersion propagating through an anisotropic medium. The calculated results are, on the whole, supported by experimental measurements on SMSW. We demonstrate that a geometry which in isotropic media leads to a sinusoidal distribution of diffraction order amplitudes as a function of penetration into the differing lattice, can lead to a nearly exponential distribution of such amplitudes in anisotropic media. The anisotropy of the interaction between SMSW and the magnetic diffracting lattice is manifested by anomalously high scattering efficiencies for certain cases of relative orientation.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 11, pp. 76–85, November, 1988. 相似文献