开展了大靶面中波红外连续变焦光学系统设计研究, 设计出了一种机械正组补偿式连续变焦光学系统。该系统的工作波段为3.7~4.8 m, 焦距为50~580 mm, F数为4.5; 靶面直径为24.6 mm, 适用于目前新推出的像元间距为15 m 的1280×1024元制冷型中波红外焦平面探测器。在实现长焦距、高分辨率的同时, 可保持光学系统具有大视场角, 进而有效提高机载光电系统的目标搜索与识别能力。设计结果表明, 本文系统的成像质量高, 在30 1p／mm空间频率处的调制传递函数值接近0.2。

Large imaging plane middle wave infrared continuous zoom optical systems were studied. A large imaging plane mechanical positive group compensated continuous zoom optical system was designed. The system had its operation waveband of 3.7 to 4.8 m, the focal length of 50 to 580 mm, the F number of 4.5 and the image plane diameter of 24.6 mm. It was suitable for the newly launched 1280×1024 pixel, 15 m pitch middle wave infrared cooled detectors. The system could keep a large field of view and effectively improve the ability of airborne electro-optical systems to search and identify targets while achieving long focal length and high resolution. The design result showed that the system had high imaging quality and its modulated transfer function value is close to 0.2 at the spatial frequency of 30 lp/mm.