Sagnac旋光效应及Sagnac偏振器件的设想

通过将线偏光分成左右圆偏振光导入Sagnac环并沿不同方向传播,推导得2束光再相遇时组成的线偏光相比于初始偏振方向会有旋转,定义此效应为Sagnac旋光效应.利用这一效应设想可以制成通过控制Sagnac环转动来调制经过其传播的光的不同偏振方向.同时通过测量出射光相对于入射光偏振方向的旋转角,也可以得到Sagnac环的旋转角速度,据此也提供了利用Sagnac环制成的光纤陀螺仪进行惯性导航的测量思路.     

手机液晶显示器的黑白图案反转

根据液晶分子扭转排列特性,指出了光在液晶中的偏振方向扭转的角度与光在液晶中的传播距离有关,较好地解释了旋转手机液晶显示器的黑白图案反转现象.     

影响伪装目标偏振检测的偏振方向研究

基于Stokes矢量和Mueller矩阵,推导了任意偏振方向的线偏振度表达式。在入射面内改变探测角和偏振方向,通过实验室和野外偏振检测实验验证了推导结果,并以目标与背景偏振度对比为主要指标研究了影响伪装目标偏振检测的偏振方向因素。研究结果表明:探测角在镜面反射方向附近,不同偏振方向的偏振度对比波动较小;虽然野外环境的结果波动稍大,但当以偏振片最大透光轴方向垂直于入射面为参考方向时,偏振方向间隔60°和45°的偏振度对比较间隔30°稳定;计算表明偏振图对比度明显高于强度图对比度,间隔60°的偏振度对比较高,间隔45°的次之,间隔30°的偏振度对比较差,偏振检测效果不佳。     

宇宙双折射?

微波背景辐射(CMB)是宇宙中最古老的光,其偏振越来越受到关注,以寻求新物理的迹象.偏振方向的微小旋转即为一种征兆,正如光经过不同偏振方向折射率有异的双折射材料那样.这种"宇宙双折射"未被标准模型预言,可能是由CMB光子跟假想的粒子和场耦合所致.已有的实验尚未发现双折射,但实验灵敏度受到系统误差的限制.     

偏振片工作原理及标示方法建议

振动方向对于传播方向的不对称性叫做偏振,它是横波区别于其他纵波的一个最明显的标志,只有横波才有偏振现象.在高中物理光学内容中关于偏振现象主要讲述的是线偏振光,高中教材为让学生理解偏振原理就专门用一个绳波通过一个狭长的木框来说明偏振现     

椭圆偏振波的旋转方向与相移的关系

设有二振动方向相垂直、频率相同、相差一定的线偏振波,分别表为 不失一般性,令传播方向上的坐标z=0,在此波振面上有 它们的合成波为(4) 一般为如下图所示的椭圆偏振波.为求此偏振波的旋转方向.作如下考虑(结论均是对迎着传播方向而言)。 在(1),(2)中令ωt=τ,(1) i(2)得合成椭圆偏振波振动矢对应的复数表式 T的幅角为显然偏振波的 T的幅角为显然偏振波的旋转方向与　　的变化率有关,为此求出 则(3)式可写成,可见旋转方向与二线偏振波的相移　　有关,讨论如下: 若　,椭圆偏振波右旋(逆时针方向). 椭圆偏振波左旅(顺时针方向). 椭圆偏振波变…     

偏振干涉成像光谱仪中偏振化方向对调制度的影响

论述了自行研制的偏振干涉臧像光谱仪的原理,分析了其分光机理和成像原理;实在 重就起偏器、分析器的偏振化方向对干涉图调制度的影响进行了分析和计算,推导了偏振化方向偏离理想方向时调制度偏角的变化关系,给出和讨论了调制度随偏 角变化的空间曲面以及最大调制离（Ｖ＝１）和最小调制度（Ｖ＝０）时偏振器偏振化方向的空间取向。     

偏振光通过透镜的偏振状态分析

采用菲涅尔原理和琼斯矩阵理论,分析了偏振光经过透镜后偏振状态的变化规律,得到了任意入射偏振光通过单透镜后偏振状态的一般表达式,讨论了偏振光通过共焦双透镜后的偏振分布.分析结果表明对于单透镜,入射光偏振方向相对于入射面±45°时有最大的偏转量;入射偏振光在共焦双透镜作用下的偏振方向偏转量是单透镜时的2倍.     

光学一题

光学一题在偏振化方向互相正交的两偏振片Ｎ＿１、Ｎ＿２之间放一１／４波片，波片Ｐ的光轴自与Ｎ＿１的偏振化方向平行开始匀速旋转一周，周期为Ｔ。若以强度为Ｉ＿０的单色自然光通过此系统。求：（１）通过１／４波片Ｐ后，偏振态随Ｐ旋转的角度θ如何变化？（２）通过...     

超声多波聚焦及声偏振方向控制方法*

在超声多波聚焦思想的基础上,通过数值模拟计算,分析了时间反转法的多波聚焦特性以及对声场偏振方向进行控制的可行性。结果表明,在待测目标的不同位置处,时间反转法都能够实现多波聚焦的效果,使具有不同传播速度、不同偏振特性的多种声波自适应聚焦。但是,在介质的近表面处,由于受到表面波的影响,多波聚焦声场仍然具有椭圆偏振特性,无法实现声场偏振方向精确控制的目的;而位于介质内部的多波聚焦点受到表面波影响很小,数值计算结果表明此时多波聚焦声场具有线偏振特性,通过改变声源前后两个脉冲的激发幅度和相位,可以控制声场的偏振方向,达到偏振方向扫描的目的。该文的研究为精确检测裂纹方向或界面性质提供一种可能的途径。     

Absorption and generation of electromagnetic waves by structural inhomogeneities of solid

The integrability conditions of the electromagnetic field equations in a continuum with defects and their wave solutions are found. The following dislocation effects on the electromagnetic wave propagation in a continuous medium are investigated: the change in the direction of the electromagnetic wave propagation in a continuous medium; the rotation of the polarization plane of electromagnetic field wave in a continuous medium; the excitation of longitudinal components of the electromagnetic wave in a continuous medium and the change in the electromagnetic wave intensity related to this phenomenon. The energy balance equation for the electromagnetic field in a continuum with a stationary distribution of dislocation is found and it is shown that an electromagnetic wave excites exciton modes localized at dislocations in the solid.     

Electromagnetic Waves in a Medium with Screw Dislocations

It is shown that in a medium with screw dislocations oriented predominantly along one axis the rotational velocity of the plane of polarization of an electromagnetic wave is much greater when it propagates in the direction perpendicular to this axis than in the parallel direction. For a given dislocation density tensor, the conditions under which the rotational velocity of the plane of polarization of the electromagnetic wave reaches its maximum are found.     

Berry effect in unmagnetized inhomogeneous cold plasmas

The propagation of electromagnetic waves in an unmagnetized weakly inhomogeneous cold plasma is examined. We show that the inhomogeneity induces a gauge connection term in wave equation, which gives rise to Berry effects in the dynamics of polarized rays in the post geometric optics approximation. The polarization plane of a plane polarized ray rotates as a result of the geometric Berry phase, which is the Rytov rotation. Also, the Berry curvature causes the optical Hall effect, according to which, rays of left/right circular polarization deflect oppositely to produce a spin current directed across the direction of propagation.     

Test of a model coupling of electromagnetic and gravitational fields by using high-frequency gravitational waves

Models of the coupling of electromagnetic and gravitational fields have been studied extensively for many years. In this paper,we consider the coupling between the Maxwell field and the Weyl tensor of the gravitational field to study how the wavevector of the electromagnetic wave is affected by a plane gravitational wave. We find that the wavevector depends upon the frequency and direction of polarization of the electromagnetic waves, the parameter that couples the Maxwell field and the Weyl tensor, and the angle between the direction of propagation of the electromagnetic wave and the coordinate axis. The results show that this coupling model can be tested by the detection of high-frequency gravitational waves.     

The electron in the quantum field of a plane wave and the classical field of Redmond configuration

The Dirac equation is solved exactly for an electron interacting with both the quantum field of a plane wave and with a classical electromagnetic field, consisting of a plane wave and a constant, homogeneous magnetic field, parallel to the direction of propagation of both waves.     

FDTD Analysis of Electromagnetic Reflection by Conductive Plane Covered with Magnetized Inhomogeneous Plasmas

A novel finite-difference time-domain (FDTD) methodology which incorporates both anisotropy and frequency dispersion at the same time is developed for electromagnetic wave propagation in anisotropic magnetoactive plasmas in this paper. The numerical verification of the method are confirmed by computing the reflection and transmission of right-handed/left-handed circularly polarized (RCP/LCP) wave through a magnetized plasma layer, with the direction of propagation parallel to the direction of the biasing field. And, the right-handed / left-handed polarized wave reflection coefficients for electromagnetic signals normally incident upon a conductive plane covered with a layer of magnetized plasma are computed using the new FDTD method. The parabolic electron-number density profile varies only in the direction perpendicular to the plane. The function dependence of reflection coefficients on the number density, collision frequency and external magnetic field is studied.     

Faraday rotation due to quadratic gravitation

The linearized field equations of quadratic gravitation in stationary space-time are written in quasi-Maxwell form. The rotation of the polarization plane for an electromagnetic wave propagating in the gravito-electromagnetic field caused by a rotating gravitational lens is discussed. The influences of the Yukawa potential in quadratic gravitation on the gravitational Faraday rotation are investigated.     

Reversal of the dipole vortex in a negative index of refraction material

When a small particle is illuminated by a circularly polarized laser beam, the induced electric dipole moment rotates in a plane. The flow lines of the emitted electromagnetic energy are the field lines of the Poynting vector. When the particle is embedded in a dielectric, these field lines have a vortex structure, and the rotation in the vortex has the same orientation as the rotation direction of the dipole. We show that when the embedding medium is a negative index of refraction material, the direction of rotation in the vortex is reversed.     

Rotation of elliptic optical beams in anisotropic media

We investigate the linear propagation of a paraxial optical beam in anisotropic media. We start from the eigenmode solution of the plane wave in the media, then subsequently derive the wave equation for the beam propagating along a general direction except the optic axes. The wave equation contains a second-order mixed derivative term originating from the anisotropy, and this term can result in the rotation of the beam-spot. The rotation effect is investigated by solving analytically the wave equation with an initial elliptical Gaussian beam for both uniaxial and biaxial media. For both media, it is found that there exists a specific direction, which is dependent on anisotropy of the media, on the cross-section perpendicular to propagation direction to determine the rotation of the beam-spot. When the major axes of the elliptical beam-spot of the input beam are parallel to the specific direction, the beam-spot will not rotate during propagation, otherwise, it will rotate with the direction and the velocity determined by input parameters of the beam.     

Zur Beugung an öffnungen in nichtebenen Schirmen

By means of an approximate method formerly published by this author, diffraction by an aperture in a screen, which is not plane, is discussed. For the special case of a circular aperture in a funnel-shaped screen, the diffraction field on the axis behind the screen is computed for an incident scalar plane wave (different boundary conditions) and for an incident electromagnetic plane wave propagating in the direction of the axis.