长波红外连续变焦光学系统设计

Design of long-wave infrared continuous zoom optical system

针对320×240制冷型焦平面阵列探测器,根据机载红外搜索和跟踪系统使用要求,设计了一套高变倍比长波红外连续变焦光学系统。探讨了长波红外连续变焦设计方法,并对变焦系统的无热化和冷反射效应进行了分析。系统由变焦物镜系统、二次成像系统和一个反射镜构成,具有100%冷光阑效率。工作波段为8.7～11.7μm,F#为2.0,变焦范围30～300 mm,工作温度-30～50℃,在空间频率16 lp/mm处,全焦距范围和温度范围内MTF>0.45,接近衍射极限。具有像质好、分辨率高、结构紧凑、质量轻便等优点。

For 320×240 cooled detector with staring focal plane array,a long-wave infrared continuous zoom system with high zoom ratio was designed,based on the requirements of airborne infrared search and track systems.The design method of long-wave infrared zoom system was discussed,and the athermalization and narcissus effect for infrared zoom system were also analyzed.The system was composed of a zoom system,a secondary imaging system and a reflector,and held a 100% cold shield efficiency.The spectral band of the system is 8.7-11.7 μm with F# is 2.0.It can realize 30-300 mm continuous zoom and work at-30-50 ℃ temperature range.The image quality of the system approaches the diffraction limit with MTF0.45 in the whole zoom and temperature range.It has the advantages of excellent image quality,high resolution,compact size and low weight.