温度对星载空间外差干涉型光谱仪性能的影响

Thermal Effect on Optical Properties of Spatial Heterodyne Spectroscopy

为研究温度对星载空间外差干涉型光谱仪性能的影响,分析了温度变化对光谱仪中准直镜头、成像镜头以及干涉仪组件各光学系统组成部分性能参数的变化关系,建立了温度对光谱仪谱线漂移影响的模型,通过软件仿真和热光学实验对理论模型进行了验证。结果表明,良好的镜头光学设计方案可有效避免星载环境下温度对镜头组件光学性能的影响,干涉仪组件温度变化会使系统基频变化直接导致光谱谱线的漂移,同时温差过大会对光谱仪光谱分辨率产生影响,使光谱谱线发生变形。针对星载空间外差干涉型光谱仪中干涉仪组件的温控条件,应依据基频、结合光谱分辨率和带宽等性能指标提出严格的温控范围。

To study the thermal effort on optical properties of spatial heterodyne spectroscopy(SHS),the relation between the change in temperature and the degradation of optical properties was analyzed,including collimator lens,imaging lens and interferometer unit.The theoretical model was verified and corrected by simulation and thermal-optical test,which was established to describe the relation between spectral-line shift and groove density change of gratings.The results show that spectrum measurements are not affected by small temperature changes in the instrument since the primary effects are a slight defocus of the focal plane array in collimating lens and re-imaging lens under the temperature from 15 to 25 ℃.Spectral-line shift obtained by the thermal optical analysis is well coincident with the ones calculated by thermal optical experiment because of the temperature changes of interferometer unit.The Littrow wavelength accuracy is better than 2.3nm unless the temperature change is less than 2.5℃ under the interferometer unit by use of the material BK7.