超大视场红外光学镜头设计

超大视场红外光学镜头在军事上主要用于对来袭目标进行告警，相比于常规红外光学系统，其设计具有许多不同的特点。结合实际工程应用，在投影方式、光学构型、像面照度、视场、无热化、评价方式等方面对超大视场红外光学系统设计的特点进行分析。给出了一个具体的设计实例，所用探测器采用1 024×1 024@15 μm制冷型中波红外探测器，光学系统工作波段3.7～4.95 μm，焦距9.6 mm，视场116°，仅采用4片透镜实现无热化设计，不含衍射面，工作温度覆盖范围?55～+70 ℃，镜头结构紧凑，总长度小于70 mm。像质评价结果表明:全视场单个像元角分辨率均匀性95%以上，单个像元能量集中度在75%以上，光学系统边缘视场照度为中心视场照度的90%以上。

Design of infrared optical lens with large field of view

The ultra large field of view infrared optical lens was mainly used to warn the incoming target militarily. Compared with the conventional infrared optical system, its design had many different characteristics. Combined with practical engineering applications, the characteristics of the design of the infrared field system of the large field of view were analyzed in terms of projection mode, optical configuration, image plane illumination, field of view, non-thermalization, evaluation mode and so on. A concrete design example was given. The detector adopted 1 024×1 024@ 15 μm cooled medium wave infrared detector. The operating band of the optical system was 3.7?4.95 μm, the focal length was 9.6 mm, the field of view was 116°, and only 4 lenses were used to realize optical non-thermalization without diffraction surfaces, the working temperature covered a range of ?55?70 ℃, the lens structure was compact, and the total length was less than 70 mm. The results of image quality evaluation showed that the angular resolution uniformity of a single pixel in the full field of view was more than 95%, the energy concentration of a single pixel was more than 75%, and the illuminance of the optical system edge field of view was more than 90% of the central field of view.