道威棱镜的偏振特性及偏振补偿研究

为了避免机载光电吊舱中共口径光学系统内部由于道威棱镜旋转引起的激光照射脉冲偏振态的变化,利用琼斯矩阵对道威棱镜的偏振特性与四分之一波片、半波片补偿道威棱镜旋转引起的激光脉冲偏振态变化进行了理论分析和实验验证。结果表明:线偏振的激光脉冲通过旋转一定角度的道威棱镜时,激光脉冲偏振态变为椭圆偏振,偏振态发生变化;而激光脉冲首先通过旋转一定角度的四分之一波片与半波片时,可使通过道威棱镜系统的激光脉冲偏振态保持不变,且两波片旋转角度与道威棱镜旋转角度之间存在一种非线性关系。采用偏振补偿方法可有效避免机载共口径光学系统中道威棱镜引起的激光脉冲偏振态变化,提高激光脉冲能量利用率,降低激光脉冲后向散射抑制难度。     

Interferometric tolerance determination for a Dove prism using exact ray trace

We use exact ray trace to calculate the interferometric Dove prism tolerance to manufacturing errors. We model the manufacturing errors by modifying the position of the prism vertices. The normal to the prism faces establishes the direction of the rays. We determine the prism tolerance by analyzing the optical traversed path rays. We evaluate the change in the image quality introduced by the normal deviation. When the manufacturing tolerance is maintained within ±0.35 arc sec, the maximum wave-front deviation is better than λ/10 at 633 nm. We found that a Dove prism with such tolerance introduces an OPD of two orders of magnitude lesser than a commercial Dove prism. The exact ray trace accuracy of the developed program is validated with the commercially available optical-design program OSLO™. The calculated tolerance complements a previous analysis of a Dove prism for its implementation in a rotationally shearing interferometer.     

Deterministic qubit transfer between orbital and spin angular momentum of single photons

In this work we experimentally implement a deterministic transfer of a generic qubit initially encoded in the orbital angular momentum of a single-photon to its polarization. Such a transfer of quantum information, which is completely reversible, has been implemented adopting an electrically tunable q-plate device and a Sagnac interferometer with a Dove prism. The adopted scheme exhibits high fidelity and low losses.     

Optimized design of parallel beam-splitting prism

A large lateral shearing distance of parallel beam-splitting prism is often needed in laser modulation and polarization interference. In this letter, we present an optimized design of parallel beam-splitting prism and list some different cases in detail. The optimized design widens the use range of parallel beam-splitting prism. At the wavelength of 632.8 nm, the law that the enlargement ratio changes with the refractive index and the apex angle is verified.     

Three-dimensional position measurement of a levitated nanoparticle in a vacuum by a Dove prism

Forward-scattering-light interferometry has become the most commonly used position detection scheme in optical levitation systems. Usually, three-set detectors are required to obtain the three-dimensional motion information. Here, we simplify the three-set detectors to one set by inserting a Dove prism. We investigate the role of a Dove prism in the position measurement process with an optical levitation system in vacuum. The relationship between the power spectral density and the rotation angle of a Dove prism is experimentally demonstrated and analyzed. This work shows that the Dove prism can greatly reduce the complexity of the experimental setup, which can be applied to compact optical levitation systems for studies in metrology, quantum physics,and biology.     

双折射器件对机载激光雷达偏振探测影响的研究

根据膜层理论给出了机载激光雷达回波信号垂直入射偏振棱镜时偏振平行分量透过率的数学解析表达式,定量分析了偏振棱镜对机载激光雷达回波信号平行分量透过率的影响,理论计算表明：棱镜晶体厚度、空气膜层厚度及棱镜结构角共同影响回波信号通过偏振棱镜的透过率;当回波信号波长为532 nm,利用1/2石英波片测得的偏振平行通道和偏振垂直通道的增益比k为1.2时,机载激光雷达偏振通道增益比k的真实值在1.003～1.463之间,若不考虑1/2波片对k值的影响,会给退偏振比反演带来较大的系统误差.     

Solid-state interferometry of a pentaprism for generating cylindrical vector beam

We demonstrated the generation of a cylindrical vector laser beam using a pentaprism interferometer. The solid-state interferometer was made up of a trapezoid and right-angle prism, whose hypotenuse face was implemented with a polarization beam splitter coating that split a rotated TEM₀₁ mode beam into two orthogonal polarizations. The Ppolarized beam was reflected inside the prism twice, allowing a mode pattern without inversion; however, the Spolarized beam was reflected once resulting in mode patterns that form P-polarized beams rotated by 90°. We also held the phase shift of the two beams to zero by use of a phase shifter, thus the output of the superimposed beam was a radially polarized beam. We demonstrated the mode pattern and polarization purity of the output beam through the use of this configuration.     

Transmission ratio of the Glan-Taylor prism with deviated optical axes in the static polarization interference imaging spectrometer

Glan-Taylor prism is the key component of the static polarization interference imaging spectrometer. In this paper, we consider the case that optical axes of the Glan-Taylor prism have departure angles from their ideal directions that in the principal section, however principal section varies with optical axes. Ray tracing method is employed to detailedly present the light trails in the birefringent Glan-Taylor prism when the incident plane and the principal section are in the same plane. Both double refraction in the crystal and internal double reflection over the interface between the birefringent and isotropic mediums are analyzed in detail. Besides, we obtain the approximate formula about the transmission ratio of Glan-Taylor prism. Finally, the transmission ratio of Glan-Taylor prism due to the deviations of the optical axes is deduced and discussed in particular.     

用琼斯矩阵法分析别汉棱镜像面偏振态分布

 基于反射定律的矢量式易于追迹复杂系统中光线的三维空间传播方向,计算了别汉棱镜每一面反射光线的方向,利用琼斯矢量法建立每一反射平面的琼斯矩阵以及面与面之间的传输矩阵,得到了一束线偏振平行光通过别汉棱镜后像面上的偏振状态分布,即经由2个屋脊面出射的光束是2个方位角不同的椭圆偏振光,这2个方位角的大小与入射线偏振光的振动方向有关。采用斯托克斯参量测量法,对别汉棱镜像面上偏振状态的分布进行了实验检测,得到了与理论分析一致的结果,指出别汉棱镜的偏振效应将会导致出射光束偏振状态的不均匀分布。     

Sorting and detecting orbital angular momentum states by using a Dove prism embedded Mach-Zehnder interferometer and amplitude gratings

An experimental system consisting of a Dove prism embedded Mach-Zehnder (M-Z) interferometer and two gratings was built to sort and detect orbital angular momentum (OAM) states of light beams. The helical beams with different OAM states were generated by propagating the fundamental-mode Gaussian beam through a spatial light modulator. The Dove prism embedded M-Z interferometer was used to sort helical beams with odd or even OAM number and two binary amplitude gratings were used to measure the OAM states. Sorting of coaxially-superposed coherent and incoherent helical beams with odd and even OAM states was realized in the experiment.     

Compact cyclic shearing interferometer: part one

A compact cyclic shearing interferometer to be used with convergent light for testing lenses is described. It essentially consists of a combination of a prism pair and a plane mirror and is designed to eliminate the residual aberrations present in the oblique incidence interferometer. The interferometer is simple to adjust, occupies little space and is less prone to misalignment.     

Cancellation of star light generated by a nearby star–planet system upon detection with a rotationally-shearing interferometer

We derive the analytical expression for the star–planet incidance detected with a (variable angle) rotationally-shearing interferometer, with the absence of star-related quantities. The rotationally-shearing interferometer detects only the tilted wave front incident from a planet. The partial polarization of two rotated beams diminishes the signal amplitude by a factor proportional to the cosine-square of the shearing angle. The polarization considerations favor the small-angle implementation of the rotationally-shearing interferometer.     

平行光路中的三轴稳像反射镜组

在对立方棱镜的结构特性和阿贝棱镜的成像特性分析的基础上 ,提出了由反射镜组成的三轴稳像反射镜组 ,并推导了该三轴稳像反射镜组在平行光路中的稳像公式。该三轴稳像反射镜组具有体积小和适合于所有光谱范围等特点。     

A 180° rotation shearing interferometer with increased optical efficiency

Use of a rotating wedge-shaped mirror rather than a rotating prism gives a higher throughput rotation shearing interferometer. The new interferometer has polarization problems if the shear differs from 0° or 180°. However, for the commonly used 180° shear, the new interferometer offers a 4-fold reduction in time required for observations employing short-exposure sequences.     

Effect of spatio-temporal coupling on ultrafast laser direct writing in glass

Spatio-temporal coupling characteristics of ultrafast laser pulses are quantitatively tailored. An asymmetric microstructure is induced in the focal volume when the laser scans perpendicularly to the direction of the spatial chirp in fused silica. The tilted direction reverses when adding a Dove prism into the light path. The sign of the pulse front tilt can be turned from positive to negative by changing the group delay dispersion by steps. We reveal that the tilted direction of a microstructure depends on spatial chirp, and the interplay between spatiotemporal chirp leads to the change of tilted angles.     

偏转平台剪切电子散斑干涉相移技术研究

在沃拉斯顿棱镜作为剪切器件的传统剪切散斑干涉术中,由于错位的二物光束同光路传播,很难通过将它们分开来引入附加相位的方法实现相移。本文提出的偏转平台法是利用平台上物体的偏转来引入附加相位的,从而可以实现剪切电子散斑干涉的相移。理论分析证明,物体的偏转可以引入稳定、线性的附加相位,并给出了物体偏转角度与附加相位之间的关系式;利用周边固定、中心加载圆盘进行了典型实验,给出了实验结果,证明偏转平台相移技术能够有效地从干涉条纹中提取位移导数信息。     

偏振干涉成像光谱仪中Wollaston棱镜光程差及条纹定位面的精确计算与分析

论述了基于单Wollaston棱镜的偏振干涉成像光谱仪的基本原理;采用波法线追迹方法,对光以4种不同入射方式经过偏振干涉成像光谱仪中单Wollaston棱镜的精确光程差、分束角及干涉条纹定位面进行了计算,并给出它们与棱镜楔角、入射角及入射位置之间的理论公式;采用计算机模拟对光程差、分束角及条纹定位面的精确值和近似值进行分析与比较,结果表明精确值和近似值之间存在较大差异;当棱镜楔角、入射角及入射位置增大时,精确值和近似值之间的偏离量随之增大;利用得到的精确值分析了条纹定位面的偏离量及其对傅里叶透镜成像的影响 关键词： 偏振干涉成像光谱仪 Wollaston棱镜 光程差 条纹定位面     

用于角膜放射状切开手术的准分子激光器和光束投射系统

介绍了用于角膜放射状切开手术的准分子激光器和光束投射系统.得到宽0.14mm长8mm的狭缝光束.能量密度大于200mJ/cm~2.用Dove棱镜可使光束旋转.这个光学投射系统适合于动物角膜放切研究.     

Experimental analysis of the effects of orientation and location of the Pockels cell in an Nd:YAG laser resonator

We report an experimental study on the effects of the orientation and location of a Pockels cell used as electro-optic Q-switch in a laser resonator. Out of the four resonator configurations studied, it was found that in two resonator configurations a high cavity-Q value of the resonator was maintained in Q-switched operation, irrespective of the orientation of the crystallographic axis of the Pockels cell with respect to the incident plane of polarization. Further, analysis of the polarization state of the output in one of the configurations showed that it is always linearly polarized in the plane of the pass axis of the intra-cavity polarizer. In the other configuration it was observed that, as the Pockels cell was rotated, the plane of the linearly polarized output light was rotated correspondingly. For all of the resonator configurations, our experimental results are in good agreement with a Jones matrix analysis