针对单波段导航敏感器通常只能获取目标某一方面的信息, 所获信息量少、识别率低的问题, 提出一种共用孔径、多波段光学导航敏感器的设计。从光焦度分配理论出发, 给出了以主次反射镜为共用部分, 工作在不同视场的共口径光学系统的初始结构设计。可见光、红外和激光三个通道共用一个Ritchey-Chretien系统, 实现大口径的设计要求。为了实现可见光成像、红外成像与激光雷达探测功能, 在次镜表面镀制选择性透过光学薄膜, 将激光雷达的接收部分与成像系统分开。通过棱镜将Ritchey-Chretien系统的反射光路分为两路, 一路成像于可见光探测器, 一路成像于非制冷型长波红外探测器。设计结果表明, 可见光系统在90 lp/mm的MTF大于0.4, 红外系统在14.7 lp/mm的MTF大于0.4, 成像系统的传递函数接近衍射极限; 激光接收系统在距离探测器质心30 μm处的能量接收高达90％, 在-20~40 ℃成像质量良好。

A design method for a common aperture and multi-band optical navigation sensor was proposed with the aim of solving the problem in which single-band navigation sensors can only get limited information from a target, as they have a low recognition rate. The design method of the initial structure of the common aperture optical system with primary and secondary mirrors as the common part and working in different fields of view was presented based on the theory of optical power distribution. Visible, infrared, and laser channels share a Ritchey-Chretien system to meet the design requirements of a large aperture. To realize the functions of visible imaging, infrared imaging, and LiDAR detection, the receiving part of the LiDAR was separated and the use of spectroscopic elements was reduced by the selective transmission of an optical film on the secondary mirror. The image of the Ritchey-Chretien system was divided into two paths by a prism; one was to the image photodetector and the other was to the image in the uncooled infrared detector. Through a large relative aperture, the radiation response of an uncooled detector was improved. The design results show that the Modulation Transfer Function (MTF) of the visible system is above 0.4 at 90 lp/mm, the MTF of the infrared system is above 0.4 at 14.7 lp/mm, the transfer function of the imaging system is close to the diffraction limit, and the energy of the laser receiving system is up to 90% at 30 μm from the center of the mass of the detector. The imaging quality of the system is suitable at -20—40 ℃.