BiCaInVIG法拉第旋转器旋光色散的测量

对于法拉第光隔离器,法拉第旋转器45°旋转角的精确度决定了其隔离度,法拉第旋转器的旋光色散决定了其带宽。本文给出了法拉第旋转器旋光色散的测量方法,并对铋钙钒石榴石(BiCaInVIG)法拉第旋转器样品的旋光色散进行了测量。结果表明:波长越长,法拉第旋转角越小。     

BiCaInVIG法拉第旋转器旋光色散的测量

对于法拉第光隔离器,法拉第旋转器45°旋转角的精确度决定了其隔离度,法拉第旋转器的旋光色散决定了其带宽.本文给出了法拉第旋转器旋光色散的测量方法,并对铋钙钒石榴石(BiCaInVIG)法拉第旋转器样品的旋光色散进行了测量.结果表明波长越长,法拉第旋转角越小.     

磁致线双折射对法拉第旋转器消光比的影响

本文从磁光材料的介电张量出发,分析了磁致线双折射与法拉第旋转器消光比的关系,并给出了实验验证。结果表明,磁致线双折射是影响法拉第旋转器消光比的主要因素。     

由8字形回路构成的光纤隔离器

一种新型光学隔离器包含光纤法拉第旋光器而不是普通晶体。当光通过平行磁场中的石英光纤时，偏振便逐渐转动。对于足够长的光纤，偏振面可移动45”或更多。而当光反向通过光纤时，偏振不会反向转动，因此，在增添适当取向的入射和击射偏振器情况下，该旋转器可起着单路光阀的作用。光纤法拉第旋光器早在1981年提出，但几个缺点妨碍了实用性实施。。为对多数应用有足够的旋转，需要有几米长光纤，因此，光纤必须绕成线圈，以便更为紧凑。遗憾的是，只是平行于磁场的光纤部分才对旋转有贡献，因此，回路内的净旋转为零。然而，如果回路半径调…     

晶体型二阶偏振模色散模拟器

报道了一种新型的二阶晶体型偏振模色散(PMD)模拟器,其由3片可产生不同的一阶PMD差分群延迟(DGD)的晶体和1个法拉第旋转器组成,法拉第旋转器理论上可在180°内连续变化。该二阶PMD模拟器实验上能近似模拟从50到200 ps2的二阶PMD。给出了二阶PMD随偏置电压变化的曲线。实验表明,该器件输出的重复性好,响应时间小于1 ms,实验值与理论值近似符合。     

光隔离器用法拉第旋转器的Mueller矩阵形式

本文通过分析在理想情况下不同偏振态的光经过法拉第旋转器前后Ｓｔｏｋｅｓ矢量的变化，从理论上导出理想的光隔离器用法拉第旋转器的Ｍｕｅｌｌｅｒ矩阵形式。     

光纤偏振控制器的原理、结构及特点分析

光纤偏振器具有抗干扰能力强，插入损耗小，易与光纤系统连接等优点，在光纤相干通信系统．以及光纤相干传感系统中受到重视。文中系统地讨论了电磁挤压型、可旋转光纤线圈型、可旋转光纤曲柄型、法拉第旋转器型、线性双折射光纤型，以及改进型和保偏光纤伸展型等光纤偏振器的工作原理和结构，分析了它们的特点，为新型光纤偏振控制器的设计提供了参考。     

磁致圆二向色性对法拉第旋转器消光比的影响

从磁光材料的介电张量出发,分析了法拉第旋转器消光比与磁致圆二向色性的关系,在此基础上,讨论了铋钙钒BiCaInVIG法拉第旋转器磁致圆二向色性对光隔离器隔离度、插入损耗的影响.     

廉价的磁光材料

据美国Milwaukee的Marquette大学的研究者报导,一块廉价的丙稀酸塑料可用作光调制器、光或磁的传感器,即决定光束的传播方向。这种器件的基本原理-磁光效应,即法拉第旋转并不是什么新原理。但是Mar-     

精细表面下细小缺陷的磁光涡流成像实时探测

磁光涡流成像检测装置可实现精细表面下细小缺陷探测。在该装置中，通过物体表面上方的交流激励线圈实现传统的涡流感应，涡流所感应的磁场由法拉第效应来检测。为了实现表面下缺陷的检测目标，激光穿过安放在激励线圈中的特殊的磁光晶体，激光偏振方向在晶体中的旋转大小取决于检测区域磁场的大小，缺陷将使检测区域磁场分量发生变化并使偏振光的旋转角发生相应变化，通过一光学装置转化成“明”或“暗”图像，该光学装置由传统的显微镜、照明系统、偏振器和CCD图像传感器组成。给出了初步的实验探测结果。     

Nonreciprocal Electromagnetic Wave Propagation in Ionized Gaseous Media

The nonreciprocal propagation of electromagnetic waves in ionized gaseous media is discussed, and experimental observations are reported in this paper. The classical Faraday experiment in the optics of anisotropic media has suggested an analogous phenomenon at microwave frequencies. The anisotropic behavior of the free electron gas which is immersed in a magnetic field and subjected to an incident electromagnetic wave is determined. Guided microwave experiments were performed which confirm the theoretical predictions of nonreciprocal wave propagation in such ionized gases.     

斜入射时BiCaInVIG和GdYBiIG晶体旋光角变化的研究

搭建了磁光晶体的磁致偏振特性测试实验系统。利用此实验系统,在可调磁场下,对两种光通信用磁光晶体BiCaInVIG和GdYBiIG垂直入射与斜入射时旋光角的变化进行了测试。测试结果表明,该两类晶体均存在Faraday效应的各向异性。     

Review of Anisotropic Terahertz Material Response

Anisotropy is ubiquitous in solids and enhanced in low-dimensional materials. In response to an electromagnetic wave, anisotropic absorptive and refractive properties result in dichroic and birefringent optical phenomena both in the linear and nonlinear optics regimes. Such material properties have led to a diverse array of useful polarization components in the visible and near-infrared, but mature technology is non-existent in the terahertz (THz). Here, we review several novel types of anisotropic material responses observed in the THz frequency range, including both linear and circular anisotropy, which have long-term implications for the development of THz polarization optics. We start with the extreme linear anisotropy of macroscopically aligned carbon nanotubes, arising from their intrinsically anisotropic dynamic conductivity. Magnetically induced anisotropy will then be reviewed, including the giant Faraday effects observed in semiconductors, semimetals, and two-dimensional electron systems.     

An E-J Collocated 3-D FDTD Model of Electromagnetic Wave Propagation in Magnetized Cold Plasma

A new three-dimensional finite-difference time-domain (FDTD) numerical model is proposed herein to simulate electromagnetic wave propagation in an anisotropic magnetized cold plasma medium. Plasma effects contributed by electrons, positive, and negative ions are considered in this model. The current density vectors are collocated at the positions of the electric field vectors, and the complete FDTD algorithm consists of three regular updating equations for the magnetic field intensity components, as well as 12 tightly coupled differential equations for updating the electric field components and current densities. This model has the capability to simulate wave behavior in magnetized cold plasma for an applied magnetic field with arbitrary direction and magnitude. We validate the FDTD algorithm by calculating Faraday rotation of a linearly polarized plane wave. Additional numerical examples of electromagnetic wave propagation in plasma are also provided, all of which demonstrate very good agreement with plasma theory.      

Finite-Element Analysis of Optical and Microwave Waveguide Problems

A vector H-field formulation is developed for electromagnetic wave propagation for a wide range of guided-wave problems. It is capable of solving microwave or optical waveguide problems with arbitrarily anisotropic materials. We have introduced infinite elements to extend the region of explicit field representation to infirdly, to consider open-type waveguides more accurately. Computed results are given for a variety of optical planar guides, image lines, and waveguides containing skew anisotropic dielectic.     

各向异性脑组织内的电磁场分布

推导出用时域有限差分（ＦＤＴＤ Ｍｅｔｈｏｄ）计算电导率为各向异性脑组织内部电磁场的一般迭代公式,在此基础上计算了典型各向异性脑组织在几种入射情况下内部电磁场的分布,得出有益的结论。此导出的公式可应用于电磁兼容和生物效应的研究之中。     

雷电及核电磁脉冲对光纤传输特性的若干影响

介绍了强电磁脉冲作用下光纤中热量的计算方法，分析了雷电及核电磁脉冲在光纤中由克尔效应及法拉第效应产生的极化面旋转现象，最后阐述了含金属构件的光缆遭受雷电时的感应电压的计算方法。     

Electromagnetic field radiated by a point source in an anisotropic layer

The field of a point electromagnetic source localized in a homogeneous anisotropic coating of a perfect conductor is constructed by the Fourier method. The field in the anisotropic layer can be interpreted as a sum of ordinary and extraordinary waves (Felsen and Marcuvitz, 1973). The asymptotics of the electromagnetic field in the far zone is studied. Far from the surface, the main contribution is due to the outgoing spherical wave and near the coating the field is represented as the sum of waveguide modes contributions. Specific asymptotics appear in a vicinity of critical directions across which the number of waveguide modes changes.     

Analysis of an anisotropic plate Faraday rotator coated with multilayer dielectric plates

The analysis of an anisotropic plate Faraday rotator coated with multilayer dielectric plates is presented by means of the matrix methods in conjunction with Fourier transformation technigues. It provides a closed-form representation of the electromagnetic field over the whole multilayer regions. The treatment does not limit the direction of the biased magnetic field and the numbers of the coated dielectric plates. Numerical results are presented and compared with that calculated with the method in ref.[1], and full-waveguide-band bandwidth for 47.5°±1.5° rotation angle is obtained for transmission type rotator in W band. Calculation for reflection type rotator is also presented and compared with the experiments.     

Hermite-Gauss beams in uniaxially anisotropic crystals

Propagation of Hermite-Gauss beams of any order along the optical axis of a uniaxially anisotropic crystal is investigated. Starting from a general approach for solving boundary value problems in anisotropic materials, closed-form expressions of the electromagnetic field are given for this fundamental class of beams. Any optical beam in an anisotropic crystal is the superposition of ordinary and extraordinary parts, propagating independently. By analyzing the expressions of the fields originated by an input Gaussian beam, the effects of the anisotropy on the diffraction properties of the ordinary and extraordinary beams have been elucidated