基于径向偏振光的波片参数测量方法  

Parameter Measurement of Wave Plate Based on Radially Polarized Beams

作　　者：唐凡春 步扬[1,2] 吴芳 王向朝 Tang Fanchun;Bu Yang;Wu Fang;Wang Xiangzhao(Laboratory of Information Optics and Opto-Electronic Technology,Shanghai Institute of Optics and Fine Mechanics,Chinese Academy of Sciences,Shanghai 201800,China;University of Chinese Academy of Sciences.Beijing 100049,China)

机构地区：[1]中国科学院上海光学精密机械研究所信息光学与光电技术实验室,上海201800 [2]中国科学院大学,北京100049

出　　处：《中国激光》2022年第17期75-82,共8页Chinese Journal of Lasers

基　　金：国家科技重大专项课题(2016ZX02201-001);上海市科委项目(18511104500)。

摘　　要：提出了一种利用径向偏振光同时测量波片相位延迟量和快轴方位角的方法。水平线偏振光通过涡旋半波片后生成径向偏振光,然后用径向偏振光照射被测波片。由于径向偏振光具有空间非均匀分布的偏振特性,对单次检偏后采集的光强分布依次进行Radon变换和最小二乘拟合,可得到强度调制曲线。最后对强度调制曲线进行傅里叶分析,就可计算得到被测波片的相位延迟量和快轴方位角。实验结果表明,当波片的快轴与水平方向的夹角为45°时,消色差1/4波片和808nm零级1/4波片的相位延迟量和快轴方位角的测量标准差小于0.03°。该方法测量装置简单,测量过程无需转动器件,测量快速方便且测量精度高。Objective Wave plates are critical components in several fields,including precision measurement,singularity optics,and optical communication.A wave plate's phase retardation and fast axis azimuth are two key parameters.The precise measurement of these two parameters is of great significance for the use of a wave plate.The methods including photoelastic modulation method,laser frequency division method,rotating device method,heterodyne interference method,and finite element simulation method are used to measure the two parameters.These methods are effective;however,they are not without drawbacks.Vector beams have a spatially inhomogeneous polarized distribution compared to common linearly and circularly polarized beams.The polarization state of radially polarized vector beams,for example,is distributed along the radial direction at any point in the cross-section.Furthermore,all linear polarization states can simultaneously be very useful for measuring the parameters of a wave plate,and as a result,vector beams are gaining popularity in the field of polarimetry.Methods First,the measurement principle of the proposed method based on the Muller matrix and Stokes vector is described in Fig.1.Second,formulas for calculating the measured wave plate's phase retardation and fast axis azimuth are developed.Finally,the effects of the vortex retarder(VR)zero-degree fast axis error,charge-coupled device(CCD)noise,and other factors on measurement accuracy are investigated.The experimental setup is constructed based on the measurement principle.The light source in the experiment is a white-light emitting diode,which is transformed into a collimated uniform red light field of 633 nm after passing through a plane-convex lens and a bandpass filter.When the red light passes through the horizontal linear polarizer and the vortex retarder,it produces a radially polarized beam.The radially polarized beam is then passed through a measured wave plate and a vertical linear polarizer.Finally,the intensity distribution is captured by a CCD

关 键 词：测量 相位延迟量 快轴方位角 径向偏振光 波片 

分 类 号：O436.3[机械工程—光学工程]