长波红外景象模拟器投影光学系统无热化设计

Athermalization for Projection Optical System of Long-Wave Infrared Scene Simulator

基于数字微镜器件（digital micromirror device,DMD）的红外景象模拟器能够为红外系统性能测试与评估提供先进的手段。根据DMD的工作原理,确定了以分光棱镜来连接照明系统和投影系统的红外景象模拟器总体方案。探讨了红外景象模拟器投影光学系统的像差特性、光学设计和无热化的设计方法,设计了一套工作在长波红外8~12μm,F#为2.8,视场角为3°的投影光学系统,并对该系统在40~60℃之间进行光学被动式无热化设计。结果表明：该系统在所要求的温度范围内,光学传递函数均接近衍射极限,成像质量满足系统的设计要求,并具有辐射能量损失小、分辨率高、结构紧凑等特点。

The infrared scene simulator based on DMD provides the advanced means for the performance testing and evaluation of the infrared system. According to the working principle of DMD, the general scheme of infrared scene simulator is determined, that the illumination system is connected to projection system with the dichroic prism. The aberration properties and optical design and athermal design method of the projection optical system are discussed. A projection optical system is designed, which working waveband is 8~12μm long wave infrared band, F # is 2.8, the field of view is 3°. The projection system was athermalized by optical passive athermal design method at-40-60 ℃. The design result indicates that the optical transfer functions are close to the diffraction limit in the required temperature range, the image quality meet the design requirements, and the system has the characteristics with small loss radiation energy, high resolution and compact structure.