On the scattering of an obliquely incident plane wave by a biisotropic cylinder

Scattering of an obliquely incident electromagnetic plane wave by an infinitely long, homogeneous, biisotropic cylinder is addressed. The ambient host medium considered is isotropic, homogeneous and dielectric-magnetic. It is observed that the constitutive coupling of the electric and the magnetic fields in the biisotropic material causes the cross-polarization component of the scattered field not to vanish even for the normal incidence case.     

Characteristic electromagnetic waves in a circular waveguide filled with a biisotropic medium

A numerical solution is given for the problem of characteristic electromagnetic waves in a circular waveguide with a biisotropic rod. The dependences of the propagation constants of the different wave modes on the chirality parameter, nonreciprocity, and permittivity of the rod are obtained. The results presented can be useful when developing devices and measuring the parameters of biisotropic materials. State University, Tomsk. Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 2, pp. 48–52, February, 1997.     

Finding Solutions to Equations for the Longitudinal Components of an Electromagnetic Field in a Biisotropic Medium in the Neighborhood of a Regular Singular Point as Generalized Power Series

For a system of equations that describe electromagnetic fields in a biisotropic medium, particular solutions have been constructed in the neighborhood of a regular singular point. The solutions are written in the form of generalized power series. For the coefficients of the power series, exponents and recursion relations have been found. It has been shown that the solutions of the wave equations are generalizations of well-known special cylindrical functions. The behavior of the particular solutions have been examined for varied material parameters of the medium. The solutions obtained allow one to formulate mathematical models which could be used to calculate and optimize the parameters of a wide spectrum of functional devices based on waveguide structures with biisotropic inserts.     

Scattering of Plane Electromagnetic Waves from a Biisotropic Sphere in Vacuum

The boundary-value problem on scattering of a plane circularly polarized electromagnetic wave from a biisotropic sphere in vacuum has been solved. The coefficients for scattered and internal fields have been obtained and numerically analyzed.     

Isotropic Maxwell-Garnett model for biisotropic-in-biisotropic mixtures

The Rayleigh scattering response of an electrically small biisotropic sphere immersed in an ambient biisotropic medium has been utilized in constructing a Maxwell-Garnett model of a composite material formed by randomly dispersing biisotropic spheres in a biisotropic host medium. It is anticipated that this work will be of interest for estimating the electromagnetic properties of particulate media.     

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.     

源嵌入正折射率传输线介质板内的倏逝波和成像特性

 提出了点源嵌入正折射率介质板进行亚波长成像的新方法,分析了位于负折射率媒质里的正折射率介质板内外的电压倏逝波和电压传播波分布。正和负折射率媒质分别由2维未加载传输线和2维加载电感、电容传输线网络组成。微波电路和数值仿真结果都显示由于板内增大的倏逝场,在正折射率介质板的两个界面附近出现了很大的电压幅度,该结果证实了该正折射率介质板透镜能够恢复电压倏逝波,从而提高像的分辨率。     

Transverse coupling between two general biisotropic slabs

The general formulation for the determining of transverse coupling behaviour between two different biisotropic slabs is proposed based on the method of conventional field perturbation, and some special cases are considered. Since biisotropic medium is a generalization of the well-studied nonreciprocal and reciprocal chiral media, our results are suitable for much more cases.     

非线性左手材料的时域研究

 分析了非线性左手材料模型,推导了非线性左手材料中的时域有限差分法及完美匹配层的计算式。数值模拟了具有Kerr非线性效应的左手材料平板中的电磁波。观察到该材料同样具有电磁聚焦特性。对比线性左手材料,其聚焦点的幅度和位置都会发生偏移。同时改变波源的强度及其到平板边界距离,讨论了不同距离情况下该非线性左手材料平板对电磁波分布的影响。当波源距离材料平板足够远,通过非线性左手材料聚焦的电场强度几乎集中在其外表面。     

Spectral dyadic Green's function formulation for uniaxial bianisotropic superstrate-substrate structure

In this paper, spectral-domain dyadic Green's functions for the time harmonic electric current source embedded in a two-layer grounded uniaxial bianisotropic media are obtained using Fourier tranform. It is shown that in the uniaxial bianisotropic medium, total spectral electromagnetic field can also be separated into the superposition of transverse electric (TE) and transverse magnetic (TM) wave. Because of the generality of constitutive relations our results include the special cases of achiral, uniaxial, reciprocal and nonreciprocal biisotropic media.     

负折射率材料对隐失波的幅度增益

分析了隐失波透过负折射率材料制成的透镜时,可以实现相位的调整,从而实现波的聚焦的原理;另外利用叠加原理(干涉法)及场量匹配法分析了负折射率材料如何实现对隐失波的振幅的放大,得到负折射率材料对隐失波有幅度增益,行波和隐失波都能聚焦成像的结论;并利用传输线理论提出隐失波透过负折射率材料平板时可等效地形成一个LC振荡电路,从而实现对隐失波的幅度增益.     

Imaging Properties of a Rectangular-Lattice Metallic Photonic-Crystal Slab

We report the imaging properties of a two-dimensional rectangular-lattice photonic crystal （PC） slab consisting of rectangular metallic rods immersed in a dielectric background. By simulating the electromagnetic wave propagation through such a PC slab with the finite-difference time-domain method, we find that a point source placed in the vicinity of the PC slab can form a good-quality image through the slab. The frequency region where a good-quality image is formed can be controlled by choosing the direction along which the PC slab surface normal is placed.     

Folded shift multiplexing

Shift multiplexing is a holographic recording method that uses a spherical reference wave. We extend the principle to a thin slab of holographic material that acts as a waveguide. Total internal reflection folds the reference spherical beam in one dimension. We demonstrate that the shift selectivity with the folded spherical beam is independent of the slab thickness but depends instead on the numerical aperture of the coupled spherical wave. A shift selectivity of 0.5 microm has been achieved with a 1-mm-thick LiNbO3 crystal and 50 high-definition data pages are recorded with this method.     

Field of a Point Source Within Perfectly Conducting Parallel-Plates in a Homogeneous Biisotropic Medium

The spherical wave scattering response by a perfectly conducting open–ended waveguide in a biisotropic medium is obtained. Interestingly, the vector diffraction problem is reduced to the scattering of a single scalar field, this scalar field being the normal component of either a left–handed or a right–handed Beltrami field. Here, we explicitly consider the scattering of the left–handed field component, that of the other scalar field being analogously tractable. The solution is constructed with the aid of the Wiener–Hopf technique.     

不同厚度有耗左手材料板中的电磁波研究

 基于有损耗的Lorentz模型的时域有限差分（FDTD）方法,模拟了有耗左手材料（LHM）平板对波源的图像聚焦特性。分别计算了不同宽度的左手材料平板结构。通过比较说明电磁波在不同厚度左手材料板中传播方式相同。材料板越薄,其聚焦点的位置越往板边缘靠近。当左手材料板的厚度不满足聚焦尺寸时,该聚焦点将会消失。     

Photonic band structure calculations for metal-clad two-dimensional photonic crystal slab

We study the effect of metallic cladding on the band structure of a two-dimensional photonic crystal slab. Band structures of a honeycomb patterned two-dimensional photonic crystal slab, with/without a metal-clad or a perfect conductor clad, are calculated using both the finite-difference time-domain (FDTD) method and the plane wave expansion (PWE) method. We explain the changes of the band structure due to cladding. We also show that the band structure of a metal-clad photonic crystal can be obtained effectively from the odd modes of the air bridge type dielectric photonic crystal slab, thicker than the metal-clad photonic crystal by a factor larger than two.     

Radiation patterns of electric dipole antenna in the presence of a biisotropic sphere

Analytic expressions of the dyadic Green's function of an arbitrary electric current source embedded in a general biisotropic sphere are presented at first, and the radiation characteristics of an electric dipole antenna placed on the surface of a biisotropic sphere lens are examined. The effects of the electric-and the magnetic-coefficients ( _e and _m ) of biisotropic medium on the radiation patterns of electric dipole antenna are investigated in detail.     

Negative refraction and imaging properties of circular photonic crystals

The electromagnetic wave propagation in a two-dimensional (2D) circular photonic crystal (CPC) is investigated. The CPC structure is composed of air holes in the dielectric background material. The finite element method is used to study the optical and propagating properties of the CPC slab. Numerical simulations show that negative refraction and near-field imaging can appear in a 2D CPC slab. We also find that the high-symmetry CPC slab possesses an optics axis along the vertical direction intersecting the symmetric center. As a result, the CPC slab can exhibit an excellent imaging performance when a source is placed on the optical axis.     

Construct a polarizing beam splitter by an anisotropic metamaterial slab

We present a theoretical investigation of polarizing beam splitters based on an anisotropic metamaterial (AMM) slab. At the interface associated with a certain AMM, TE- and TM-polarized waves exhibit opposite amphoteric refraction characteristics, such that one polarized wave is positively refracted whereas the other is negatively refracted. The opposite amphoteric refractions result in a large birefringence in the AMM slab. By suitably using the large birefringence, we introduce a very simple and very efficient beam splitter to route the light. We show that the splitting angle and the splitting distance between TE- and TM-polarized beams is the function of anisotropic parameters, incident angle and slab thickness. PACS 41.20.Jb; 42.25.Gy; 78.20.Ci