空间调制偏振干涉成像光谱仪的核心是干涉仪, 干涉仪的重要组成部分是Savart偏光镜。Savart偏光镜的透射率直接决定着空间调制偏振干涉成像光谱仪的光通量, 进而影响到目标的干涉图和目标的像。因此有必要研究Savart偏光镜的透射率对光通量的影响。在介绍干涉仪结构的基础上, 利用电磁场边界条件和折射定律分别求得了光在Savart偏光镜的4个分界面：空气/Savart偏光镜的左板; Savart偏光镜的左板/胶粘剂; 胶粘剂/ Savart偏光镜的右板; Savart偏光镜的右板/空气的透射率和光强, 同时得到了光通过干涉仪后的两束干涉光的光强。利用光的叠加原理得到了干涉后的总的光强, 并求出了光通过Savart偏光镜的透射率和光通量的数学表达式。通过两者的关系式可以很直观的看到Savart偏光镜的透射率对空间调制偏振干涉成像光谱仪的光通量的影响, 为研究空间调制偏振干涉成像光谱仪提供了一定的理论依据。

The interferometer is core of spatially modulated polarization interference imaging spectroscopy, the key component of the interferometer is Savart polariscope. The throughput of spatially modulated polarization interference imaging spectroscope is directly determined by transmissivity in Savart polariscope, thus affects forming the interferogram and target image. There is necessary to study the influence of transmission in Savart polariscope on throughput. After introducing the structure of interferometer, on the basis of electromagnetic field boundary conditions and the law of refraction-transmission and light intensity were obtained in Savart polariscope of the four interfaces: air /the left plate of Savart polariscope; the left plate of Savart polariscope/adhesive; adhesive/the right plate of Savart polariscope; the right plate of Savart polariscope/air, at the same time the light intensity is got after the two light beams interfere in through interferometer.The interference overall intensity is obtained by using light superposition principle,the mathematical expression of the transmissivity and throughput is solved. Through the relationship between the transmissivity and throughput, the influence of transmissivity in Savart polariscope on throughput can be intuitively known, this may provide a theoretical basis for the study of spatially modulated polarization interference imaging spectroscopy.