动态目标模拟离轴三反光学系统的设计

以同轴三反像差理论为基础,运用仿真软件确定满足设计要求的初始结构参数,基于三镜同轴,入射光束离轴,主镜和三镜顶点相交的光学设计理念,设计出一种易于装调、精度保证的离轴三反光学系统。该系统结合数字微镜器件目标生成器为装甲车辆提供动态实时模拟目标。该光学系统的工作波段为200~1200nm,焦距为2800mm,视场为2°,入瞳直径为350mm。设计结果表明,本光学系统最大相对畸变为0.1056%,各视场的波像差均优于λ/40(主波长λ=636.3nm)。在70lp/mm下,本系统的调制传递函数(MTF)均优于0.54,接近衍射极限,成像质量好,满足无穷远动态目标模拟需求;对加工和装配进行公差分析后可知,光学系统的MTF值大于0.4。

Design of Off-Axis Three-Mirror Optical System for Dynamic Target Simulation

This study determines the initial structural parameters based on the theory of coaxial three-mirror aberrations to satisfy the design requirements using a simulation software.Through the optical design concept of coaxial three mirrors,incident beam off-axis,primary mirror,and third-mirror vertex intersecting,an off-axis three-mirror optical system,which can be easily adjusted and exhibits high accuracy,is designed and combined with a digital micromirror device target generator,thereby providing a dynamic real-time simulation target for an armored vehicle.The system has a working waveband of 200-1200 nm.Further,the effective focal length is 2800 mm,the field of view is 2°,and the diameter of entrance pupil is 350 mm.The design results prove that the maximum relative distortion of the optical system is 0.1056%.Furthermore,the wave aberration of each field of view is better thanλ/40(the dominant wavelengthλ=636.3 nm),and the modulation transfer function(MTF)is greater than 0.54 at 70 lp/mm,which is close to the diffraction limit.The system also exhibits a good imaging quality,satisfying the requirements of an infinite dynamic target simulation.In addition,by the analysis of the machining and assembly tolerance,the MTF of the optical system greater than 0.4 can be obtained.