Enhancement of circular differential deflection of light in an optically active medium

In this letter, we investigate the circular differential deflection of a light beam refracted at the interface of an optically active medium. We show that the difference between the angles of deviation of the two circularly polarized components of the transmitted beam is enhanced manyfold near total internal reflection, which suggests a simple way of increasing the limit of detection of chiro-optical measurements.     

Gaussian beam parameter transformation at a refracting surface

The Fourier transform method is used to calculate the electric field of the astigmatic gaussian beam which appears when an incident stigmatic gaussian beam is refracted at the interface between media with different refractive indices. A beam parameter transformation law is derived which shows that the beam parameters of the refracted astigmatic beam can be calculated from the beam parameters of the incident stigmatic beam and the angles of incidence and refraction. An heuristic derivation of the transformation law based on geometrical optics is also given. The application of the law is illustrated by determining the plane parallel plate astigmatism.     

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     

光自旋霍尔效应中横移的影响因素研究

研究了光束在空气与电介质分界面传输产生的自旋霍尔效应,揭示了光束重心横移分别与偏振态、折射率差以及入射角三者之间的定性关系.研究发现各光场横移都随偏振参量增大而增大,左、右旋椭圆偏振光的横移等值反向,圆偏振态下的横移比椭圆偏振态下的横移大.改变折射率差的大小,反射光横移随折射率差的增大而减小,但当折射率差接近零时,反射...     

液-液界面上折射声束位移的实验验证

对折射波束在液-液界面上的现象进行了数值和实验研究，结果表明：当声束从声阻抗大的介质入射到液-液界面上时，折射声束会存在反向位移现象。     

Electromagnetic wave refraction on the interface of absorptive and transparent isotropic media and non-resonant excitation of surface waves

New formulae for the angles of refraction at the interface of the absorbing/transparent isotropic media are derived from Maxwell's equations. Using the time-averaged Poynting vector for the direction of the beam of light, the noncoincidence of incidence and refraction planes is predicted for the mixed polarization of incident wave. The angle between the refracted beam and incidence plane is especially large for the condition of non-resonant excitation of surface electromagnetic waves at a flat interface of absorptive-transparent media.     

A generalized approach to beam wave interaction with a dielectric interface

New phenomena have been reported recently in connection with Gaussian beam interaction with a plane dielectric interface, namely, the deterioration of the reflected and refracted beams from shapes predicted by geometric optics, and the generation of higherorder components that cause angular beam deflection. Any bounded, symmetric beam, which is not necessarily Gaussian, can be comprised in terms of an angular spectrum of plane waves. Utilizing such a modal expansion, a model of the interaction process that seems to point out the generality of the phenomena involved for bounded symmetrical beams with any cross-section is presented. The procedure is applied to a Cauchy profile, and analytical results are given. Comparison with previous results obtained for the Gaussian beam and careful examination of the respective spectral functions demonstrate close correspondence between the results. This adds credence to the general approach presented here which can be applied to bounded symmetrical beams of general shape.     

拉盖尔-高斯光束在界面反射和折射的质心偏移特性研究

在圆柱坐标系中研究了傍轴线偏振拉盖尔-高斯光束在两种各向同性介质界面反射和折射后光强质心的偏移. 基于菲涅耳近似和泰勒级数展开,分别得到了部分反射和全反射两种情形下,质心的横向偏移和纵向偏移与光束拓扑荷的解析关系式. 研究表明,部分反射时,反射和折射光束的横向偏移的大小与光束的拓扑荷成正比,方向由拓扑荷的符号决定;而纵向偏移仅仅大小与光束的拓扑荷有关. 全反射时,反射光束质心偏移不受拓扑荷影响. 通过数值模拟验证了解析结果的正确性,并得到了解析公式的适用条件. 拉盖尔-高斯光束的质心偏移特性可应用于测量光 关键词： 拉盖尔-高斯光束 横向偏移 纵向偏移 拓扑荷     

Conservation of angular momentum, transverse shift, and spin Hall effect in reflection and refraction of an electromagnetic wave packet

We present a solution to the problem of reflection and refraction of a polarized Gaussian beam on the interface between two transparent media. The transverse shifts of the beams' centers of gravity are calculated. They always satisfy the total angular momentum conservation law for beams, but, in general, do not satisfy the conservation laws for individual photons as a consequence of the lack of the "which path" information in a two-channel wave scattering. The field structure for the reflected and refracted beams is analyzed. In the scattering of a linearly polarized beam, photons of opposite helicities are accumulated at the opposite edges of the beam: this is the spin Hall effect for photons, which can be registered in the cross-polarized component of the scattered beam.     

基于粒子成像测速技术的水中气泡界面的光学性质研究

基于粒子成像测速的流体可视化技术，根据菲涅耳公式计算了入射到水中气泡界面的光强，得出点光源连续两次反射或折射的光强具有等比数列的规律，光线在气泡界面反射、折射4次就变成完全偏振光且光线几乎消失.当入射角避开35°左右时，即便有一定宽度的线光源入射到气泡界面，第2次折射出气泡的光强与线光源的宽度无关，类似一条光线入射所产生的光强，给出了面光源在界面所产生的光强的二重积分表达式.线光源所产生的界面光强理论值、面光源产生的光强数值解与实验值都较为符合. 关键词： 水中气泡 界面 光强 粒子成像测速     

Refractive index profiling of a GRIN optical fiber using a modulated speckled sheet of light

A method for calculating the refractive index of GRIN optical fiber from its transverse interference pattern is presented.In this method the transverse interference fringe pattern through an optical fiber using a sheet of light is applied to get the refractive index profile of it. The optical fiber is not immersed in a matching liquid as used in different techniques [Barakat N, El-Hennawi HA, El-Zaiat SY, Hassan R. Pure Appl Opt 1996;5:27].In this method a sheet of He–Ne laser light is allowed to illuminate the fiber. The light sheet is divided into two parts, the first is refracted through the fiber while the second is used as a reference beam. Interference pattern will be obtained between these two rays displaying the refractive index variation along the fiber radius.The fringe shift of such interference pattern has been measured and used to calculate the deflection angle of light refracted by the fiber and the cladding. An equation is derived to calculate the refractive index profile difference ratio δn at different positions across the fiber cross section in terms of the corresponding deflection angle and is verified experimentally.The optical path difference between these two rays (refracted and reference beam divided by the fiber) has been derived and the fringe shift obtained has been used to calculate the refractive index profile of the fiber.Introducing a ground glass screen on the passage of the two light beams (refracted and reference beam divided by the fiber), two superimposed identical speckle patterns are formed leading to the formation of a third speckle pattern modulated by a grid structure displaying the optical thickness of the fiber.     

The influence of rock anisotropy on elliptical-polarization state of inhomogenously refracted P-wave

This paper discusses the influence of the anisotropy parameters on elliptical-polarization of the inhomogenously refracted P-wave induced at VTI-media interface. For this refracted P-wave, we have derived, the equations of the elliptical-polarization trajectory. Following the elliptical-polarization trajectory, we calculated the effects of the rock anisotropic-parameters on the polarization state, with a Poincaré-sphere-like representation, for several varying media parameters. It is noted that the size, shape and initial phase angle of the elliptical-polarization trajectory are all depending the anisotropy media, as well as on the incident-angle. We expect that the findings from this paper would be applied to practical applications of seismic exploration.     

Influence of the Measurement Volume on the Phase Error in Phase Doppler Anemometry. Part 1: Reflective mode operation

In phase Doppler anemometry (PDA), phase difference errors are caused by the Gaussian intensity distribution of the laser beam and the curvature of the phase fronts outside of the beam waist. This results in erroneous particle sizes. Based on a physical analysis by geometrical optics [1], this phase difference error is evaluated for reflected mode operation (Part I) and for refracted mode operation (Part II). By varying the particle trajectories statistically, the error in determining the particle size and the mass flow can be simulated. By the method described the error in the measured phase difference can easily be estimated.     

高斯波束在双负媒质中的传播特性分析

 提出了一种基于Drude色散媒质模型的2维TM模时域有限差分法,数值模拟了高斯波束从自由空间垂直入射和斜入射到双负媒质(介电常数和磁导率同时为负)平板后的折射现象,并给出了平板内外的电场强度分布。模拟结果显示：垂直入射时,双负媒质平板对高斯波束具有汇聚作用,通过改变媒质的折射率,可以控制高斯波束通过组合平板的传播时间而不发生衰减;斜入射时,折射波束与入射波束均位于法线的同一侧,高斯波束在双负媒质与空气交界面处发生了负折射。     

The determination of electron density profiles from refraction measurements obtained using holographic interferometry

The angles a fourth-harmonic holographic interferometer probing beam is refracted upon passing through a neodymium laser-produced plasma have been measured by varying the focus during reconstruction of the hologram. A method (not requiring the numerical inversion of an integral equation) for using such refraction measurements to give the plasma electron density profile is shown to produce a profile in agreement with that obtained from the phase information on the reconstructed in-focus interferogram.     

Features of the refraction of glancing light rays from optically less dense absorbing media

A study is made of the refraction of glancing light rays at the interface of two optically homogeneous media, one of which is absorbing. Experimental data indicate an increase by several times in the flux of the refracted rays in the case of refraction of glancing rays from absorbing slabs. It is shown that the dispersion zone of deflection of the light rays partly transmits glancing rays in a transparent slab and can be opaque in weakly absorbing slabs. It is established that the increase in the intensity of the refracted beams is due to the more effective transformation of the glancing rays moving in the dispersion zone into refracted rays. Data are available on the dependence of the refracted flux on the relative refractive index.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 3, pp. 57–60, March, 1981.I thank V. E. Zuev, S. D. Tvorogov, and M. V. Kabanov for their interest in the work and discussion of the results.     

Light refraction from air in glass in the case of light beam departure from the refracting surface

The effect of light refraction in the case of a light beam departing from the refracting face of a prism is examined in this paper. It is established that the refracted flux diminishes to zero as the angle of departure increases to 14°; the angle of refraction is independent of the angle of departure, and equals the angle of refraction of glazing rays. The nature of the distribution of the refracted ray intensity along the refracting face is determined. Data are presented about the intensity distribution in the refracted beam at the exit from the prism and in the plane of the radiation detector.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 12, pp. 55–58, December, 1987.The author is grateful to V. E. Zuev and S. D. Tvorogov for attention to the research and discussion of its results.     

Beam and phase effects in angle-beam-through-transmission method of ultrasonic velocity measurement

The accuracy of a plane wave approximation for phase velocity measurements in isotropic and anisotropic material using the angle-beam-through-transmission method has been investigated numerically and experimentally. In this method the velocity is measured in different propagation directions as a function of incidence angle. The effect of two factors on the measurement accuracy have been discussed: intrinsic phase shift of the transmitted signal through a fluid-solid interface and beam diffraction due to the finite beam size of receiver and transmitter. It is shown that the interface-induced phase shift can introduce an error in time delay measurements of the shear wave after the first critical angle and that this time delay error can be accurately corrected for. Numerical results obtained by a time-domain beam model show that except at the critical angles, the finite width of the transmitter and receiver only affects the amplitudes of the transmitted signals and has almost no effect on the measured zero-cross time delay; therefore the plane wave approximation for obtaining phase velocity from the measured time delay data by this method and the plane wave interface-induced phase correction are fully applicable.     

Total reflection in a uniaxial crystal–uniaxial crystal interface

Considering an interface between two uniaxial birefringent crystals, four reflected and four refracted waves for each incidence direction are obtained. Along this direction can propagate an ordinary wave and an extraordinary wave. Here, we present the analytic expressions for the four critical angles, from which each refracted wave no more exists as propagating wave. We show the variation in these critical angles for different interfaces varying the orientation of the incidence plane with respect to the optical axes. When both principal refractive indices of the second medium are smaller than those of the first medium, then the four critical angles exist for each incidence plane and for any direction of the optical axes. But, when one of the indices has an intermediate value between the values of the indices of the other crystal, we can chose the optical axes directions in such a way that certain critical angles do not exist. Therefore, we can select the refracted wave that is eliminated by total reflection.     

Wave propagation in an anisotropic metamaterial with single-sheeted hyperboloid dispersion relation

We investigate the wave propagation in an anisotropic metamaterial with single-sheeted hyperboloid dispersion relation. Based on boundary conditions and dispersion relations, we find that the opposite amphoteric refraction, such that E (or H)-polarized waves are positively refracted whereas H (or E)-polarized waves are negatively refracted, can occur at the interface associated with the anisotropic metamaterial. Under a certain condition, both E- and H-polarized waves can exhibit the same single-sheeted hyperboloid or straight line dispersion relation, while the two polarized waves exhibit different propagation characteristics. We expect some potential device applications can be derived based on the unique amphoteric refraction properties. PACS 78.20.Ci; 41.20.Jb; 42.25.Gy