旋转波片Stokes偏振仪是最常用的测量光束偏振态的仪器。 波片快轴方位误差是影响旋转波片Stokes偏振仪的主要误差源之一。 为了研究波片方位偏差对测量精度的影响, 提出了一种描述波片快轴方位误差向最终的偏振测量误差传递的数学模型, 并引入协方差矩阵法表征偏振测量误差。 根据这一模型, 获得最优的偏振仪配置参数。 在推导过程中, 假设波片方位误差服从同一高斯分布。 基于此误差模型, 得到如下结论: (1)由波片方位误差引入的测量误差与光强测量次数N成反比； (2)测量误差独立于入射光强度, 但是依赖于入射光偏振态(s1, s2, s3)和波片的位相延迟量δ； (3)波片位相延迟量在(10322°, 11613°)范围内时波片方位误差引入的测量误差最小。 最后, 经过仿真实验证明, 所得解析结果与仿真模拟结果相一致。

Rotatable retarder fixed polarizer (RRFP) Stokes polarimeters are widely used to detect the state of polarization of light. The orientation error of the retarder is one of important error sources of RRFP Stokes polarimeters. In order to investigate the effect of the orientation errors of retarder on measurement results, a new analytical model is proposed to express the polarimetric error resulted from it, and a methods based on covariance matrix is used to express the polarimetric error. In addition, according to the analytical error model, the optimal polarimeter configuration is obtained. During derivation, we suppose that the angular orientation errors of the retarder obey a uniform Gauss distribution. Based on the analytical model derived, it can be concluded that (1) the measurement errors induced by the angular orientation error of the retarder is inversely proportional to N; (2) the measurement errors are independent to the incident intensity s0, but seriously depend on the incident state of polarization (s1, s2, s3) and the retardance of the retarder δ; (3) the retardance ranging from 10322° to 11613°, whihc results in the minimum measurement errors induced by the orientation errors of the retarder. Finally, simulation is performed to prove that these analytical results derived agree well with simulation results.