双扫描镜空间成像系统偏振特性分析

光线非垂直入射到光学界面时会产生偏振效应,且偏振效应随着入射角度的增加显著增强。双扫描镜空间成像系统具有宽光谱、大入射角、大孔径的特点,因此具有较大的偏振灵敏度。由于光电探测器的转化效率对偏振光而言不是各向同性的,而且有时差别很大,为保障光学系统探测灵敏度必须限定光学系统偏振灵敏度。采用斯托克斯矢量和穆勒矩阵的偏振表示方法,推导得出入射角度与双扫描空间成像系统偏振灵敏度之间的数学关系。通过对薄膜设计参数进行一定的工艺修正得出各个光学元件偏振数据,进而得出整个双扫描成像系统的偏振灵敏度。分析结果表明,在可见光波段双扫描成像系统的偏振灵敏度在0.5%左右;在红外波段双扫描空间成像系统偏振影响很小。

Analysis of polarization characteristic of Dual scan space imaging system

The non-perpendicular light incident to the optical interface will produce a polarizing effect, and the polarization effect is significantly enhanced with the increase in the angle of incidence. Dual scan space imaging system has a wide spectrum, large angle of incidence and aperture; therefore, it will produce large polarization sensitivity. Since the conversion efficiency of the photo-detector is anisotropic, sometimes very different, the polarization sensitivity of the optical system must be limited. In this paper, we derived mathematical relationship between the incident angle and the polarization sensitivity of the dual scan space imaging system using Stokes vector and Mueller matrix polarization method. We conducted technical amendments to the film design parameters and then got the polarization data of various optical components. Applied the data into a mathematical formula and got the polarization sensitivity of the dual scan space imaging system. The analysis results showed that the polarization sensitivity in the visible band was about 0.5%; and it almost had none effect in the infrared band.