长波红外连续变焦光学系统设计

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。

Design of long-wave infrared continuous zoom optical system

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 MTF>0.45 in the whole zoom and temperature range.It has the advantages of excellent image quality,high resolution,compact size and low weight.