超宽温折衍混合红外搜索跟踪光学系统设计

Design of infrared diffractive/refractive search and trace optical system beyond normal temperature

为满足红外搜索跟踪成像系统的环境适应性的特殊要求，设计了一种用于搜索跟踪的红外超宽温成像系统，其工作波段为3．7-4．8μm，视场角为11．42°。该系统采用三片式结构，使用锗和硅两种红外材料，引入两个非球面和一个衍射面，使系统具有结构简单、体积小、重量轻、成本低等优点。设计结果表明；该系统在-80-160℃温度范围内成像质量接近衍射极限，适用于像元尺寸为30μm、像元数为320x240的焦平面阵列探测器，保证了红外搜索跟踪系统在超宽温度下稳定的工作性能，对该系统的探测距离进行了估算，系统能够探测1．0km处的目标。

To meet enviroment performance of infrared search and trace optical system,a novel optical system beyond normal temperature of infrared camera in 3.7-4.8 μm with 11.42 degrees of field of view was designed. The IRST system was consisted of three lenses,including two aspheric surfaces and a diffraction surface, which had only two materials Ge and Si. The optical system had compact structure, small volume and light weight. The image quality of the system approached the diffraction limit in the temperature range -80-160℃. It was compatible with staring focal plane array which had a format of 320 ×240 and the pixel pitch of 30μm,the infrared search and trace system have jarless and good performance beyond normal temperature. The recognition distance of the system was calculated. The system can recognize a vehicle target from 1.0 kin.