基于MEMS的收发分置的全景激光雷达系统  

MEMS-Based Panoramic LiDAR System with Separated Transmitting and Receiving Modules

作　　者：王润 苏宙平 Wang Run;Su Zhouping(Jiangsu Provincial Research Center of Light Industrial Opto-electronic Engineering and Technology,School of Science,Jiangnan University,Wuxi 214122,Jiangsu,China;School of Science,Jiangnan University,Wuxi 214122,Jiangsu,China)

机构地区：[1]江南大学理学院江苏省轻工光电工程技术研究中心,江苏无锡214122 [2]江南大学理学院,江苏无锡214122

出　　处：《光学学报》2024年第18期341-347,共7页Acta Optica Sinica

摘　　要：设计一款基于微机电系统(MEMS)扫描的全景激光雷达光学系统,该系统可以实现在水平方向对周围环境360°环扫。该系统包含环状透镜、异形棱镜及MEMS微振镜。光源出射的光束经过异形棱镜的球面进行会聚,会聚后的光束经过MEMS反射后进入棱镜,在棱镜内部经过一次全反射,从棱镜中折射并水平射出,水平方向发散角已达0.32°。当光束进一步经过环状透镜时,垂直方向的发散角也被压缩至0.13°。通过模拟发现,当MEMS扫描到不同位置时,出射光束在水平和垂直方向的发散角都分别保持在0.32°和0.13°附近。该系统的发射和接收单元位于MEMS双侧,模拟结果表明接收系统可以有效接收周围环境散射回来的光信号。该系统使用的元件数量较少,结构简单,光效率高,且不需要任何额外的转动的光学元件,为实现大视场的激光雷达提供一种有价值的方案。Objective LiDAR plays a crucial role in vehicle-assisted and autonomous driving by detecting the surrounding environment and aiding in obstacle avoidance.Micro-electro-mechanical system(MEMS)-based LiDARs offer rapid scanning speed,high resolution,and cost-effectiveness,which makes them widely used commercially.A MEMS-based LiDAR with a 360°field of view can comprehensively scan the scene around a vehicle,which offers significant practical value.However,conventional optical systems struggle to achieve consistent outgoing beam divergence angles in both horizontal and vertical directions due to their asymmetric fields of view when attempting 360°scanning.To tackle this challenge,we present a panoramic LiDAR optical system based on MEMS scanning.It enables 360°horizontal scanning of the environment using a torus lens,anamorphic prism,and MEMS mirror.Simulation results demonstrate that our design maintains outgoing beam divergence angles at approximately 0.32°horizontally and 0.13°vertically across different MEMS placement configurations.Methods The MEMS-based scanning LiDAR system comprises two modules:the transmitting module and the receiving module.The transmitting module includes laser LA,anamorphic prism P1,MEMS,and torus lens L,while the receiving module consists of anamorphic prism P2 and detector D.In the transmitting module,the laser beam emitted by LA undergoes refraction through the special spherical surface S1 on top of anamorphic prism P1.This beam converges after passing through surface S1 and then enters MEMS through the lower surface S2 of anamorphic prism P1.After reflection by MEMS,the beam passes through region A of prism P1 where total internal reflection occurs.The beam then moves into region B where it undergoes refraction before being output.The beam exiting region B is further collimated by toroidal lens L and finally output with a small divergence angle in the horizontal direction.By rotating the MEMS mirror 360°around the Z-axis,the LiDAR achieves a scanning field of view of 360°.The

关 键 词：光学设计 激光和激光光学 激光雷达 全景扫描 异形棱镜 环状透镜 

分 类 号：O439[机械工程—光学工程]