星载光栅光谱仪消偏器性能研究

Research on the depolarizer performance of the space-borne grating spectrometer

星载光栅光谱仪中的光栅有着强烈的偏振响应。为了保证光谱仪测定的光谱分布的准确性,必须在光辐射进入仪器光谱测量部分之前就消去光辐射的偏振。应用矩阵光学推导出了这种紫外石英消偏器的残余偏振度,并得到影响其消偏性能的几个因素。建立了一套测试系统,在300-360nm波段上对其消偏性能进行了研究,得出入射光经过紫外石英消偏器后的残余偏振度变化范围1.2%-5.7%。与理论推导有较好的一致性。并按照国际通用不确定度评估规范,对测量结果进行不确定度分析和评估,组合不确定度小于1.8%。

The main portion of the space-borne grating spectrometer--grating has intense polarization response. For ensure the spectrum distribution accuracy determining by the spectrometer, the polarization of the ray radiation must be depolarized before the ray radiation entrance the spectral measurement part of the device. The residual polarization degree of depolarizer is calculated with the matrix optical theory and some factors effecting the depolarizing performance is obtained. A testing system is established, the researching on the depolarizing performance at the wave range of 300--360nm are done, and the variation range 1.2%--5.7% of the residual polarization degrees are obtained after the incident light pass by the depolarizer. It has a good consistency with the theory calculating. The uncertainty of the result is analyzed and evaluated, according to the international evaluating criterion. The total uncertainty is less than 1.8%.