为降低成像光谱仪对工作平台体积质量的需求, 优化光路布局, 提高系统的热适应性, 阐述了一种紧凑型红外成像光谱仪的光学系统设计。考虑结构尺寸和像差平衡, 光学设计中引入了扩展多项式面型。系统光谱范围为1~3.4 μm, F/数为2.86, 光谱采样间隔为7.5 nm。光学系统由一个自由曲面三反射镜望远镜和一个基于平面光栅的自由曲面光谱仪组成。望远镜准远心设计, 与后方远心光谱仪光瞳匹配, 无畸变且像方空间便于其他结构模块布局。光谱仪像质优良, 光谱畸变校正良好, 像面倾斜得到改善便于探测器布局。从光栅衍射效率设计、杂散光抑制和光机一体化集成镜件设计三方面对该系统作了分析, 结果表明系统具有工程可行性。

To reduce the burden of the working platform, optimize the optical structure and promote the thermal adaption of the imaging spectrometer, an optical design of a compact infrared imaging spectrometer was presented. Due to compactness and aberration correction, the extended polynomial surfaces were utilized in the optical design of the infrared imaging spectrometer with spectral region between 1 μm to 3.4 μm, optical speed of F/2.86, and spectral sampling of 7.5 nm. The optical system was comprised of a free form three mirror telescope and a plane grating based free form spectrometer. The telescope was semi telecentric for pupil matching with the telecentric spectrometer, free of distortion and able to provide enough imaging space for other modules. The good imaging quality of spectrometer, and spectral distortion correction were achieved, and the tilt of image plane for detector arrangement was improved. The system is analyzed from the diffraction efficiency of the grating, the supressed stray light, as well as the opto-mechanical design of the integrated mirrors, which show it has high engineering feasibility.