全景环形成像傅里叶变换光谱仪光学系统设计

Optical design of panoramic annular imaging Fourier transform spectrometer

提出了一种可以实现红外全景环形光谱成像的新型傅里叶变换成像光谱仪结构,该成像光谱仪以共焦双曲反射镜组作为全景环形集光器,利用Schwarzchild物镜进行准直,结合弹光调制干涉仪,成像透镜组以及HgCdTe红外焦平面阵列构成。介绍了全景环形成像傅里叶变换光谱仪基本工作原理及成像特性,讨论了双曲面反射全景环形集光器和Schwarzchild物镜准直器等各光学结构的设计方法,并给出了设计结果及优化方案。最后,采用Zemax光学设计软件对系统进行了光线追迹和优化,结果表明,成像光谱仪工作在8μm^12μm波段,有效焦距为-0.67mm,侧向视场为40°~80°,F~#0.9,像点弥散斑RMS半径为20.116μm,在一个像元直径内,MTF在16lp/mm处均高于0.5,且各视场一致性较好,OPD像差在±0.4λ范围内,成像质量良好。

A novel imaging Fourier transform spectrometer structure was proposed,which included two confocal hyperboloid mirrors as the collector and a Schwarzchild objective for collimating,combined with the photo-elastic modulator based interferometer,imaging lens and HgCdTe focal plane array,then the infrared panoramic annular spectral imaging was achieved.In this paper,the working principle and imaging features of panoramic annular imaging Fourier transform spectrometer were introduced,the design of two confocal hyperboloid mirrors based annular collector and Schwarzchild objective based collimator were discussed in detail,then the design model and optimization scheme were presented.Finally,the ray tracing and optimizing were done by Zemax.Results show that,the working band of designed imaging Fourier transform spectrometer is 8μm^12μm,the effective focal length is-0.67 mm,the lateral field of view is 40°~80°and the F number is 0.9,the root-mean-square(RMS)spot radius is 20.116μm less than a pixel,all field modulation transfer function(MTF)at 16lp/mm are higher than0.5with good consistency,the optical path difference(OPD)is within ±0.4λscope,the ima-ging quality of the system is fine.