Radiation of electromagnetic fields in biaxially anisotropic media* (original) (raw)
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Plain electromagnetic waves in anisotropic media
2011
A new analytical approach to description of electromagnetic waves in nonmagnetic anisotropic media is presented. Amplitudes of their reflection and refraction at interfaces and also reflection and transmission of plane parallel plates are derived. Beam splitting at reflection, and creation of surface waves at the interfaces are studied. A simple laboratory demonstration of the beam splitting is proposed. D'yakonov surface waves, their description and observation are discussed.
Radiation of electromagnetic fields in uniaxially anisotropic media*
Journal of the Optical Society of America, 1976
The angular spectrum of plane waves representation is obtained for the electromagnetic field radiated by a localized current source in a uniaxially anisotropic medium. The linear medium is homogeneous throughout all space. It may be absorbing and temporally dispersive but is not spatially dispersive. The conductivity and permeability are scalar constants. The time behavior of the source is arbitrary except that its magnitude is always bounded and it begins radiating at a finite time. The representation of monochromatic fields radiated by time-harmonic sources is included also in the results. The radiated field is expressed as a superposition of monochromatic ordinary and extraordinary plane waves propagating in various directions. The spectral amplitudes of the plane waves are determined explicitly in terms of the source. The orientation of the guide axis of the representation with respect to the optic axis of the medium is arbitrary. The form of the solution is particularly appropriate for the study of diffraction, reflection, and refraction at plane boundaries.
Bulk and surface plane electromagnetic waves in anisotropic media
A new analytical approach to description of electromagnetic waves in nonmagnetic anisotropic media is presented. Amplitudes of their reflection and refraction at interfaces and also reflection and transmission of plane parallel plates are derived. Beam splitting at reflection, and creation of surface waves at the interfaces are studied. A simple laboratory demonstration of the beam splitting is proposed. D'yakonov surface waves, their description and observation are discussed.
Physics-Uspekhi, 2012
A new effective analytical approach to describing electromagnetic waves in nonmagnetic anisotropic media is proposed. An analytical description of the refraction and reflection at an interface between isotropic and anisotropic media is demonstrated. Beam splitting upon reflection and refraction is reviewed, and surface wave generation is examined. D'yakonov surface waves and methods of their observation are discussed. Analytical and numerical calculations of the reflection and transmission of plane-parallel uniaxial plates are outlined.
International Conference on Laser Physics 2010, 2010
We investigate light wave propagation through a one-axis anisotropic medium layer with simultaneously non-unit dielectric and magnetic tensors. 4x4 -Δ matrix is built. We consider the general case when the dielectric and magnetic permittivity tensor elements have both positive and negative sings. We obtained the dispersion equation and then built dispersion surfaces for a homogeneous anisotropic uniaxial material when the material is negative or positive (both with respect to the wave vector and Pointing's vector orientation of the refracted wave; the sign of the material is accordingly defined below.) Electromagnetic plane waves propagating inside the medium can exhibit dispersion surfaces in the form of ellipsoids of revolution, hyperboloids of one sheet, or hyperboloids of two sheets. The conditions of negative refraction with respect to the wave vector and Pointing's vector orientation are considered. We found wave nonreciprocity for the oblique incidence on the considered system and we showed that such a system can work as an alloptical diode.
Refraction and reflection from the interface of anisotropic materials
In this paper the reflection and refraction of the electromagnetic waves from the planar interface of an anisotropic medium are investigated. The considered anisotropic medium is a uniaxial material whose optical axis lies in the incident plane and makes an arbitrary angle with the normal to the interface. It is shown that the directions of the wave and Poynting vectors of the transmitted wave depend on the incident angle and the orientation of the optical axis of the uniaxial material. Also, the situation that the negative refraction can happen for such media is obtained. In addition, the dependence of the Brewster angle to the orientation of the optical axis of the uniaxial material is considered. More interestingly, it is shown that there is a situation for which the wave and Poynting vectors of the transmitted transverse magnetic wave are parallel.
Electromagnetic fields in planarly layered anisotropic media
Geophysical Journal International, 2007
This paper presents a method for calculating the electromagnetic field from a dipole source in stratified media with general anisotropy. The formulation can be applied to geophysical applications such as ground-penetrating radar and marine controlled source electromagnetic (CSEM) methods. In stratified media, the propagation of fields can be considered in the frequencywavenumber domain. The resulting set of ordinary differential equations consists of a field vector, a system matrix, and a source vector. In each piecewise homogeneous region, the system matrix is given by the material properties and the horizontal slownesses. The vertical slownesses are the eigenvalues of the system matrix. A diagonalization of the system matrix transforms the field vector into a mode-field that contains upgoing and downgoing field constituents. For system matrices that account for general anisotropy, it is shown how the electromagnetic field from any of the four basic dipole types can be calculated at any desired position in the stratified medium. It is furthermore shown how the reflection and transmission response from a stack can be calculated by a recursive scheme. Potential numerical instabilities due to using propagators are avoided by using this reflectivity method. Due to an energy-flux normalization of the eigenvector matrices, the reciprocity relations for reflection and transmission of electromagnetic fields in general anisotropic media can be derived. Several other useful relations between the reflection and transmission matrices are obtained as well. The propagator method is dependent on the ability to calculate eigenvalues and eigenvectors of the system matrix for all layers. In simple cases with isotropy or transversal isotropy in the direction of medium variation, the eigenvalue problem can be solved explicitly. These eigenvector matrices have useful properties, e.g. when processing data. The possibility to remove layers above or below the receiver layer follows from the decomposition of a field into upgoing and downgoing polarization modes. The propagator theory was implemented in order to model anisotropy in marine CSEM. A modelling study shows that responses are affected by horizontal, vertical, and dipping anisotropy in different manners. This suggests that when anisotropy is present at a survey site, careful planning and interpretation are required in order to correctly account for the responses.
Theoretical and computational study of reflection and refraction of electromagnetic waves with ppp-polarized and normal incidence electric wave amplitude vector on anisotropic, inhomogeneous and linear medium has been done. The medium used in this study is a model of susceptibility in the form of rank-2 tensor which its value depends on the frequency, position and time. Theoretical and computational formulation of transmittance and reflectance are then tested using vacuum and FeF$ _2$ magnetic material.
In this study, the problem of wave scattering of an electromagnetic field in a homogeneous bi-isotropic medium by a perfectly conducting strip is theoretically analyzed. The crux of the study is a rigorous construction of a closed form solution in the complex domain. A series solution of electromagnetic plane wave diffraction problem in terms of the eigenfunctions that happen to be the generalized Gamma functions is found. In the transformed domain, the scattered field is physically interpreted by computing the convergence history, and thereby, higher order accurate solution has been obtained in complex domain in closed form.
On the Scattering of Electromagnetic Waves by Periodic Rough Dielectric Surfaces: A BOA Solution
IEEE Transactions on Geoscience and Remote Sensing, 2000
A new approach for the scattering of electromagnetic (EM) waves from periodic dielectric rough surfaces is addressed. The method is an extension of the buried object approach (BOA), which is developed for rough surfaces of infinite extend, to the present problem. The BOA allows to model the original problem as the scattering of EM waves from cylindrical objects located in a two-half-space medium with planar interface. Then, the problem is reduced to the solution of a Fredholm integral equation of second kind through the periodic Green's function of two-half-space medium. The periodic Green's function of two-half-space medium is calculated via the Floquet mode expansion, whose numerical evaluation can be accelerated by using effective methods. The method can also be used to solve the scattering problems of rough surfaces of infinite extend and having a localized roughness. Numerical simulations show that the method yields effective and accurate results for surfaces of arbitrary variation.