非制冷中波红外光学系统精简无热化设计

Simplification Athermalized Design of Uncooled Medium Wave Infrared Optical System

红外光学系统相比于可见光光学系统,其成像质量受温度波动影响很大。基于光学被动式无热化原理,分析红外系统各部分光学参量受温度变化的影响因子,设计了一个工作波段3~5μm,焦距120mm,F#=2的红外光学系统,选用分辨率为384pixel×288pixel、像元大小为25μm的非制冷型红外探测器。该系统采用四片式的结构形式且全部为球面光学元件,采用硅和锗两种常见的中波红外材料满足了消热差和消色差的要求,故具有较高的加工可行性和较低的生产成本,在工作温度范围-40℃~60℃之间都能保持优良像质,并且满足非制冷型中波红外系统的使用需求。

Infrared optical system differing from visible optical system,the imaging quality is influenced by the change of temperature. On the basis of analyzing the influence of temperature on infrared optical parameters and the fundamental principle of passive optical athermalization,an infrared optical system is designed working in the medium wave infrared 3~5μm,which focal length is 120 mm and F#=2. The pixels of uncooled detector are 384×288 and the single pixel is 25μm. The system adopts a four-piece structure and all spherical optical components. Two common medium-wave infrared materials, silicon and germanium, are adopted to satisfied the correction requirements of athermalization and achromatic aberration. Therefore,it has high processing feasibility and low producing cost;the image quality is good under-40℃~60℃;the use requirements of uncooled medium wave infrared optical system can be met.