带摆镜的二维扫描制冷红外光学系统设计

Design of two-dimensional image space scanning cooled infrared optical system with tilt mirror

带摆镜的像方扫描光学系统通常只在一维方向扫描成像,当摆镜在二维方向摆扫成像时,摆镜方位俯仰耦合运动带来的对光轴指向、光斑尺寸、成像性能等影响不能忽略。分析了不同的摆镜扫描光学系统的基本形式,并对像方摆镜扫描光学系统二维摆扫带来的影响进行了分析。对内轴为方位、外轴为俯仰的像方摆镜在不同的二维摆扫角度下的入射光轴指向和窗口处光斑尺寸进行了理论计算,提出了二维像方摆镜扫描光学系统设计与分析方法。利用Zemax建立了二维像方摆镜扫描光学系统模型,仿真分析了不同方位俯仰摆扫角度下的成像性能、光轴指向以及窗口挡光情况。在不同方位俯仰角度下,光学系统在17 lp/mm处MTF均大于0.4,窗口极限挡光小于21.4%。

Image space scanning optical system with tilt mirror usually only scanning imaging in one dimension,when tilt mirror is scanning imaging in two dimension, the effect of the tilt mirror’s coupling motion of azimuth and pitch can not be ignored. The basic forms of scanning optical system with tilt mirror were analyzed, and the influence of two-dimensional motion of the image space scanning optical system with tilt mirrors was analyzed.The incident optical axis direction and the spot size on the optical window at the different two-dimensional scanning angles were calculated. A method of image space two-dimensional scanning optical system with tilt mirror design and analysis were proposed. Building the image space two-dimensional scanning optical system model with Zemax, and the imaging performance, optical axis direction and window blocking at different angle of scanning were simulated and analyzed. Under different azimuth and pitch angles, the MTF of the optical system was greater than 0.4 at 17 lp/mm, and the max window blocking of the window was less than 21.4%.