用于激光测距的小F数接收光学系统设计

为解决远距离漫反射激光测距系统能量损耗严重问题，并提高测距系统的响应速度，设计了一种小探测靶面大通光孔径的接收镜头。以3组4片式Petzval结构作为接收镜头的初始原型，将孔径光阑前移放置在第一面，同时增大其孔径以提高接收效率，最后一片引入非球面，以减小球差并使系统小型化；靶面采用直径为75 μm的雪崩光电二极管探测器，保证响应速度小于45 ns。经过优化设计得到通光孔径为120 mm的接收镜头，F数为0.6，可用于远距离漫反射激光测距领域。

Design of small F-number receiving optical system for laser ranging

In order to solve the serious problem of energy loss in long distance diffuse reflection laser ranging system and improve the response speed of ranging system,a receiving lens with small detecting target surface and large clear aperture was designed.The three groups of 4-slices Petzval mode were used as the initial prototype of receiving lens,the aperture diaphragm was placed forward in the first side and its aperture was increased to improve the receiving efficiency.The concave of the last lens was designed as aspheric shape,which aimed to reduce the spherical aberration and miniaturize the system,and an avalanche photodiode detector with the diameter of 75μm was used for the target surface to ensure the response speed was less than 45 ns.The receiving lens with the clear aperture of 120 mm is obtained by the optimized design,and its Fnumber is 0.6,which can be used in the field of long distance diffuse reflection laser ranging.