为了使微小型无人机光电吊舱能够实现红外热成像系统小型化并适应不同的环境条件，基于光学被动无热化方式，通过合理分配不同材料透镜的光焦度并同时引入衍射面，设计了一种工作波段为8～12 μm、视场为24.5°×19.7°、F数为1.0的非制冷无热化红外成像光学系统。该系统由四片透镜组成，其总重量仅为35 g。光学系统的总长度为38 mm。结果表明，本文系统具有结构简单紧凑、后截距大、成像良好等特点，在30 1p/mm空间频率处的调制传递函数(Modulation Transfer Function, MTF)值大于0.3，满足应用需求。

In order to meet the requirements of miniaturization of thermal imaging system and different environmental conditions in the electro-optic POD of micro-mini UAV, an uncooled infrared imaging optical system with field of view of 24.5°×19.7° was designed by means of optical passive athermalization, reasonable distribution of focal degrees of lenses with different materials and introduction of a binary optical element. Its operating wavelength range is from 8 μm to 12 μm， F number is 1.0. The system consists of four lenses with a total weight of only 35 g， and the total length of the optical system is 38 mm. The result shows that the system structure is simple and compact, the back working distance is large, and the imaging quality is high. The modulated transfer function (MTF) value at the cutoff frequency of 30 lp/mm is greater than 0.3, which satisfies the application requirements.