折反式望远系统全视场全口径偏振特性研究

Study on polarization characteristics of full-field and full-pupil in refractive and reflection telephoto system

针对单根光线追迹方法在部分偏振光条件下无法对系统进行全面评价的问题,基于斯托克斯表示法提出了全视场、全口径光线追迹方法,通过对原有折射与反射穆勒矩阵表达式的优化,建立入射光偏振度、光线角度等参量与出射光偏振度的解析关系;理论分析结果表明,入射角与折射角的差值控制在5.7°以内,可以有效减少系统对光线偏振度的影响;依据空间目标成像需求设计了集成微偏振片阵列的偏振成像系统,成像分辨率500 km处为0.5 m;采用动态数据交换机制对光学系统进行全视场、全口径光线追迹,得到系统斯托克斯矢量及偏振度的全视场分布,实现对系统任意视场偏振度的标定,提升偏振探测精度。亦可通过任意视场与中心视场偏振度匹配入射光偏振度,反演目标。

In order to solve the evaluation problem of optical system under partially polarized light conditions caused by single ray tracing method,a full-field,full-pupil ray tracing method based on Stokes notation was proposed.The refractive and reflection Mueller matrix expressions were improved.The analytical relationship among the degrees of polarization(DOP)of the incident light,the ray angle and the DOP of the emitting light was analyzed.The analysis results show that when the difference value between the incident angle and the emergence angle was less than 5.7°,the influence of the system on the DOP of the light can be reduced effectively.According to the space target polarization imaging requirements,a polarization imaging optical system with micro-polarizer array(MPA)was designed.The resolution was 0.5 m at the distance of 500 km.Dynamic data exchange(DDE)was used to trace the full-field and full-pupil rays for the optimized optical system.Four Stokes vectors and full-field polarization distributions were both calculated and displayed.Due to the DOP of any field of view can be calibrated,the polarization detecting accuracy of the optical system was improved.Therefore,the target can be recognized by matching the DOP of the incident light and the DOP of any field of view.