卡式红外光学系统光机分析及结构优化

Optomechanical analysis and structure optimization of infrared Cassegrain optical system

光学仪器通常都工作在一定的温度环境中,温度变化将造成光机系统的结构尺寸以及光学介质的特性等参数发生变化。针对卡式红外光学系统工作环境温度变化范围大的特点,进行了热补偿结构设计。并利用有限元方法,对主镜及其支撑结构进行了分析,明确了导致镜面变形和结构参数变化的主要因素为大范围的温度变化。在此基础上,对支撑结构进行了改进和参数的优化设计。研究结果表明:改进后的结构是合理可行的。

Generally, optical instruments work under a given temperature condition, so the properties of optomechanical system, such as structure dimensions and optical materials＇ characteristics, are modified when experiencing temperature changing. A thermal compensation structure was designed for the infrared Cassegrain optical system working over a wide temperature range. The primary mirror and its supports were analyzed using finite element method （FEM）. It was found that the wide temperature variation is the main factor that results in both mirror surface deformation and structure parameters modification. Based on the analysis, an improved support structure was designed and optimized. The FEM results show that the improved support structure is rational and feasible.