为仿真现实场景中目标和干扰的光谱分布差异, 设计了一种基于双数字微镜器件(DMD,Digital Micro-mirror Device)的双通道、共口径、变焦光学引擎, 包括投影光学系统和两套照明光学系统.光学引擎以红外中波和长波柯勒远心光路分别直接照明两DMD靶面, 采用空间立体布局避免不同光路间干扰.设计结果表明: 照明光学系统的照度均匀性优于94%; 中波(3.7~4.8 μm)和长波(8~12 μm)内, 变焦投影光学系统在10 1p/mm处的调制传递函数(MTF, Modulation Transfer Function)值分别优于0.7和0.4; 系统畸变小于0.5%, 满足使用要求.

In order to simulate the spectral distribution difference between the target and the interference in real scene, a zoom optical engine with two channels and the same caliber has been designed based on dual digital micro-mirror device (DMD), it includes projection optical system and two illumination optical systems. The optical engine directly illuminates two DMD target surfaces respectively with long-wave infrared (LWIR) and mid-wave infrared (MWIR) Kohler telecentric beam. It uses spatial stereoscopic layout to get avoid of interference between different optical paths. The design result shows that the illuminance uniformity of illumination optical system is better than 94%. The modulation transfer function (MTF) values of zoom projection optical system are better than 0.4 and better than 0.7 at 10 1p/mm respectively in bands of LWIR (8~12 μm) and MWIR (3.7~ 4.8 μm). And the distortion is better than 0.5%, which meet the requirements.