基于制冷型探测器的双波段红外光学系统无热化设计

Athermalization Design of a Dual-band Infrared Optical System with Cryogenic Detector

针对640×512阵列双波段制冷型探测器,设计了一套双波段红外光学系统,用于机载红外搜索跟踪系统。该光学系统采用锗、硒化锌和硫化锌组合,实现了消色差和消热差设计,通过引入非球面和构型优化,很好地校正了系统的高阶像差,简化了系统结构。光学系统仅由8个镜片构成,工作波段为3.7~4.8μm和8~9.4μm波段,F数为2,焦距360 mm,视场2.54°×2.03°,满足100%冷光阑效率。像质评价结果表明,光学系统在-55^+70℃温度范围内,双波段成像质量良好。非均匀温度场分析表明,光学系统温度梯度容忍性较好。

A dual-band infrared optical system is designed for the dual-band cryogenic detector of 640×512 array which can be used in the airborne infrared search and tracking system.The optical system adopts the combination of Ge Zns and ZnSe to achieve the achromatic and athermalization design.By introducing aspheric surface and configuration optimization the high order aberration of the system is well corrected and the system structure is simplified.The optical system consists of only 8 lenses with the working bands of 3.7~4.8μm and 8~9.4μm,F-number of 2 the focal length of 360 mm and the FOV of 2.54°×2.03°meeting the 100%efficiency of a cold aperture.The image quality evaluation results show that the imaging quality of the optical system is good in the temperature range of-55℃to+70℃.The analysis of non-uniform temperature field shows that the optical system has a fine temperature gradient tolerance.