偏光干涉法测量波片相位延迟量和厚度

基于偏光干涉理论,提出一种宽光谱范围内测量波片相位延迟量和厚度的方法。利用矩阵光学方法分析了光谱透射率曲线与中值透射率直线交点波长之间的关系,给出待测波片的相位延迟量、波片厚度等多个物理量的计算公式并进行了误差分析。误差分析表明本方法相位延迟量测量最大误差为3.38°,厚度测量最大误差为0.66μm。实验上利用分光光度计验证了本方法的有效性。本方法能够实现波片多物理量的同时测量,且调节过程对于起偏器、检偏器透光轴方向及待测波片快轴方向无严苛要求,测量过程对波片也无损伤和污染,在波片加工、使用前质量评估等方面都具有一定的应用价值。     

基于最小二乘拟合的波片相位延迟测量

提出一种精密测量波片相位延迟的新方法.将待测波片置于起偏器和检偏器之间,通过步进电机控制波片匀速旋转,基于最小二乘法拟合出射光强随波片方位角变化的曲线,进而得到波片延迟.根据上述原理,建立了一套波片延迟测量系统,并分析了系统的稳定性、可测量的延迟范围、接收器件的非线性效应、系统误差源这4个影响测量精度的主要方面.结果表...     

基于光弹调制技术的波片相位延迟量测量方法

提出了一种基于光弹调制技术的波片相位延迟量测量方法,利用米勒矩阵对其进行了理论推导和误差分析。测量光路包括激光器、起偏器、光弹调制器、被测波片、检偏器和光电探测器,利用探测信号的归一化基频分量和二次谐波分量精确计算出被测波片的相位延迟量。该方法能测量紫外到红外光谱范围内任意相位延迟量的波片,误差分析表明其误差小于0.05°。实验验证了该测量方法的有效性,波片相位延迟量的重复测量精度为0.0048°。     

晶体相位延迟量的测量

通过2束平面偏振光的合成推导出椭偏测量的基本原理,给出了用标准1/4波片测量晶体相位延迟量的测量原理.在测量时不必知道待测晶体的具体光轴方位,只需调节标准1/4波片、待测晶体的快(慢)轴与起偏方向平行,然后将晶体逆时针转过45°.测量装置采用了步进电机带动检偏器旋转,使用光电探测器采集数据,经计算机处理,根据数据曲线直接读出待测晶体的相位延迟量.该方法可以方便快捷地测量任意相位延迟.     

1/4波片相位延迟分布的动态测量

通过密勒矩阵和斯托克斯参量法对一种1/4波片的相位延迟分布的测量模型进行了推导,并设计出一种空间分光移相器,取代一般测量系统中的检偏器,使得系统能于瞬间同时采集四幅具有90°移相步长的干涉图,避免了环境振动对测量的影响,从而可以对1/4波片的相位延迟分布进行动态在线测量.对一个实际标称波长632.8 nm的1/4波片进行了测量,结果显示其平均延迟量为149.36 nm,且接近75%部分其相位延迟误差在5 nm之内,显示出较好的延迟均匀性.     

基于双光束检偏的波片测量系统

大口径太阳望远镜中常用波片来进行偏振定标和偏振测量,为了对这类波片的延迟量和方位角进行准确测量,提出一种基于双光束检偏的波片测量系统,建立了该系统对应的数学模型。测量系统中检偏器的方位角可作为参数进行拟合,克服了单光束测量系统中检偏器方位角误差的影响;同时,根据测量系统的结构,对待测波片的延迟量范围进行分析,实现了对偏振定标和偏振测量中所使用波片的精确测量。分析了测量系统误差的主要来源,包括光源光强噪声、电机定位误差和探测器非线性响应,并对探测器非线性响应进行了校正。该方法测量1/4波片和127°波片的延迟量和方位角误差小于0.02°,测量27°～145°和215°～333°范围波片样品的延迟量和方位角误差小于0.05°。     

消色差λ/4波片的系统级标定方法研究

消色差/4波片具有一定的二向色性和相位延迟量误差,导致仪器偏振测量产生误差。从考虑全偏振CCD相机自身偏振效应的辐射模型入手,借助积分球辐射源和高精度辅助旋转偏振器,研究系统级非理想消色差/4波片的标定方法。结果发现:消色差/4波片的二向色性和相位延迟量参数随仪器的工作波长与带宽发生变化,波段650 nm（相位延迟量88.90）和750 nm（相位延迟量88.65）消色差效果相对较好,而波片在波段850 nm（相位延迟量84.33）相位量偏差较大;通过相位延迟量的标准误差分析,得出消色差/4波片的系统级标定方法精度优于0.8。     

基于双频激光干涉相位检测的高精度波片测量

波片精度对偏振光学系统性能有着重要的影响,故需要对其相位延迟量和快轴方位角进行高精度测量。提出了一种新型基于双频激光干涉相位检测的高精度波片测量方法,采用双频激光外差干涉光路,利用一个可旋转半波片和一个角锥反射棱镜测量待测波片,可实现任意波片的相位延迟量和快轴方位角的高精度同时测量。所提方法不受波片、偏振片等双折射器件的方位角精度的影响,从原理上避免了该类系统误差。所设计的系统具有共光路结构,测量稳定性高,信号处理采用相位检测方式相对于一般的光强检测方式测量精度更高。此外,所设计的测量系统中元件很少,结构简单,测量过程快捷。误差分析表明,在现有实验条件下,测量系统的波片相位延迟量的测量不确定度约为3.9′,快轴方位角的测量不确定度约为5′′。实验比对结果表明,所提方法的测量结果与其他方法测量结果的一致性很好。重复性测量实验表明,测量结果的标准偏差约为2′。     

测量任意波片相位延迟量的简便方法

为了更方便的测量待测波片的相位延迟量,提出了简便易行的测量任意波片相位延迟量的方法,无需标准1/4波片,而且还可以利用一套实验系统同时测量2个未知波片的相位延迟量,并从理论上推导出了通用测量公式,从实验上进行了实际测量.     

基于单光弹调制器的米勒矩阵测量技术

针对已有米勒矩阵测量方法的不足,提出了一种基于单光弹调制器的米勒矩阵测量技术,给出了米勒矩阵测量优化算法及系统参数两步校准法。该技术通过两步校准法对系统参数进行校准测量,利用优化算法计算得到待测样品的米勒矩阵。实验结果表明,待测1/4波片相位延迟量测量值为90.4185°,误差在标称偏差λ/300以内,快轴方位角测量值为0.2348°,误差在最大旋转误差0.4°以内。同快轴方位角为0°的1/4波片标准米勒矩阵相比,待测1/4波片米勒矩阵各元素最大相对误差的直接测量值和间接测量值分别为1.97%和0.83%,均小于最大相对误差的模拟仿真值2.11%。通过提高旋转台的读数精度和减小相位延迟量的标称偏差,可以进一步减小米勒矩阵各元素的最大相对误差。     

Spectral technique for measuring phase retardation of a wave plate

We present a technique and algorithm for measuring the phase retardation of a wave plate based on spectral transmission curve. Through accurately extracting the intersection points' wavelengths from the spectral transmission curve, the effective phase retardation, absolute phase retardation, order, and physical thickness of the wave plate can be measured simultaneously in a wide spectral range. Experimental results show that the proposed technique has many advantages, such as higher data utilization, simpler extraction algorithm, and no strict requirement for the directions of transmission axes of the polarizer and analyzer, and the fast axis of the wave plate.     

Simple method for simultaneous determination of the phase retardation and fast axis of a wave plate

A simple method for simultaneous determination of the phase retardation and fast axis of a wave plate is presented. In this method, double light path compare system is adopted to achieve better accuracy. In the main optical path, laser beam passes successively through a polarizer, a wave plate to be measured, an analyzer, and then is incident on a detector. In the reference optical path, another detector is used to monitor the fluctuation of the light source. With rotation of the wave plate, the maximum and minimum output light intensity, rotation angle of the wave plate are detected in the main light path; corresponding light intensity are simultaneously detected in the reference light path. Based on the light intensity and the rotation angle, the phase retardation and fast axis of the wave plate can be determined simultaneously. The main advantage of this method is its simplicity of apparatus, easy operation, low cost, and high accuracy. We believe that the method reported in this paper should be a useful approach to measure a wave plate without requiring any complex and expensive components.     

椭偏法测量云母波片相位延迟量及双折射率(英文)

为了得到云母波片的相位延迟量和双折射率随波长的变化关系,利用椭偏光谱仪连续测量了云母波片在400～770nm光谱范围内的延迟量.在对云母波片进行校准后,测量的数据被光电探测器收集并输送到计算机,根据输出的数据可以得到云母波片的相位延迟量随波长的变化.利用测得的延迟量计算出了云母波片在一定光谱范围内的双折射率,得到了云母波片的双折射率色散曲线,并通过拟合得到了双折射率色散公式.该方法能测量任意波片的相位延迟量,并且具有测量方便、周期短、精度高等特点.     

Method for measuring retardation of a quarter-wave plate based on normalized secondary harmonic component

A method for measuring retardation of a quarter-wave plate based on normalized secondary harmonic component is proposed, and the measuring principle is analyzed. The optical measuring system is composed of a laser, a polarizer, a phase modulator, the quarter-wave plate to be measured, an analyzer and a detector. The azimuths of the transmission axes of the polarizer and the analyzer with respect to the modulating axis of the phase modulator are +45°, 0°, respectively. The retardation of the quarter-wave plate is calculated precisely using the normalized secondary harmonic components prior to and after 22.5° rotation of the quarter-wave plate. In this method, the major axis position of the quarter-wave plate is not required to be known in advance, and the measured retardation is independent of the intensity fluctuation of the light source. The feasibility of the method is verified by the experiments.     

Double-pass self-spectral-calibration of a polarization state analyzer

We present a new method that allows efficient spectral calibration for a polarization state analyzer. The procedure does not require any additional polarization optical element other than the polarization state analyzer itself. It uses a double-pass technique that can be achieved up to a very good precision. The method is illustrated using real measurements done at several wavelengths with a rotating wave plate polarization state analyzer. Alignment of axis as well as true retardation at a specific wavelength are easily obtained by a standard function fitting.     

Method for rapid measuring retardation of a quarter-wave plate based on simultaneous phase shifting technique

A method for rapid measuring retardation of a quarter-wave plate based on simultaneous phase shifting technique is presented. The simultaneous phase shifting function is realized by an orthogonal grating, a diaphragm, an analyzer array, and a 4-quadrant detector. The intensities of the light beams from the four analyzers with different azimuths are measured simultaneously. The retardation of the quarter-wave plate is obtained through the four light intensity values. In this method, the major axis position of the quarter-wave plate need not be determined in advance. In addition, the measured result is free of the intensity fluctuation of light source. The feasibility of the method is verified by the experiments.     

二元复合波片延迟相位方位效应探讨

在多级波片方位效应的基础上，探讨了复合波片的方位效应问题。通过对多级波片的设计与测量，论证了入射光方位是影响波片延迟量的关键因素。     

激光回馈波片位相延迟测量的误差源及消除方法

激光回馈法是一种新型的波片位相延迟测量方法。将波片放置在激光器与回馈镜之间,可使激光回馈波形产生偏振90°旋转（即跳变）现象,而两偏振态所占的周期比（占空比）与波片的位相延迟相关。通过测量占空比即可由计算机自动给出波片位相延迟。采用双向扫描回馈镜,2次获得并测出占空比,这样可以很好地消除两偏振态损耗的波动造成的测量误差,提高了该方法长期测量的稳定性。测量的重复性达到0.5°。该方法结构简单,在线测量精度高,满足工业化生产的需要。     

Alternative method for measuring the phase retardation and fast axis of a wave plate

Optical Review - An alternative method is proposed for simultaneously measuring the phase retardation and fast axis angle of a wave plate by utilizing a radially polarized symmetric light beam. A...