高均匀性长波红外远心照明系统设计

基于数字微镜器件(DMD)的红外景象模拟器可在室内环境下模拟真实景物及其环境的红外辐射,实现对红外成像系统性能的准确测试与评估。照明系统作为红外景象模拟器的重要组成部分,为其提供红外辐射能。为使光束均匀照射在DMD器件表面,通过分析研究黑体特性及朗伯定律,确定采用像方远心光路作为照明系统的结构形式。以拉氏不变量为依据研究确定的照明系统特性参数,能够实现与投影系统完美衔接。根据设计参数完成对照明系统初始结构的计算,利用ZEMAX进行调制、优化,并完成像质评价。设计结果表明,以此方式设计的照明系统均匀性高、球差小,可进一步提高模拟仿真效果。

Design of High Uniformity LWIR Illumination System Based on Telecentric Light Path

The infrared scene simulator based on digital micro-mirror device (DMD) can test and evaluate the perfor-mance of infrared imaging system by simulating the infrared radiation of the real object and environment in the indoor environment. The illumination system is an important part of the infrared scene simulator. A main function of the illumi-nation system is to provide the infrared radiant energy for the infrared scene simulator. The illumination system is deter-mined by learning Lambert's Law and studying the characteristics of black body. The system with telecentric beam path in image space is designed to get uniform illumination on the surface of DMD device. According to the Lagrange invariant of the whole optical system of each surface of the object space value is unchanged,the characteristic parame-ters of the illumination system are determined. And the system can achieve the perfect convergence with the projection system. The initial structure of the illumination system through the way of manual calculation is modulation and optimi-zation. The image quality of the system is evaluated by ZEMAX software. The design results show that the strength of illumination is uniformity highly and the spherical aberration is small,which could conform to the requirements.