基于2D微电子机械系统(MEMS)镜全向激光雷达光学系统设计

为了满足全向激光探测的需求，提出一种基于2DMEMS镜扫描的激光雷达结构。激光器通过1×6高速光开关分时地给6个扫描子系统提供光信号，6个扫描子系统探测视场叠加起来可实现360°激光探测。每个扫描子系统的扫描范围为60°×30°，其中包含一个扩展MEMS镜扫描角度的发射光学天线和一个大视场有增益的接收光学天线。发射光学天线将MEMS镜±10°的扫描角扩展到±30°，发散度小于0.2mrad；接收视场内的激光波经过接收天线在探测器上所成的半像高小于1mm，接收增益为3.65。通过计算修正后的激光雷达方程可得到发射功率20 W的激光束在工作距离100 m内的回波功率≥1 nW，结果表明该光学系统可适用于激光雷达系统。

Design on omnidirectional optical system of lidar based on 2D MEMS mirror

In order to satisfy the omnidirectional laser detection, a structure of lidar based on 2D micro-electro-mechanical systems (MEMS) mirror scanning was proposed. The laser provides light signals to 6 scanning subsystems through a 1×6 high speed optical switch and it realizes 360° horizontal scanning by adding the field of view of 6 scanning subsystems together. The scanning range of each scanning subsystem can reach 60° × 30°, including a transmitting optical antenna that expands the MEMS mirror scanning angle and a large field of view(FOV) receiving optical antenna with gain. The transmitting optical antenna extends the scanning angle of the MEMS mirror from ±10° to ±30°, and the divergence is less than 0.2 mrad. The half image height of the laser echo in the receiving field angle passing through the receiving antenna on the detector is less than 1 mm and the gain of the receiving optical antenna is 3.65. By calculating the corrected lidar equation, the laser beam with a transmitting power of 20 W can achieve an echo power of ≥1 nW within a working distance of 100 m, and the result shows that the optical system can be applied to lidar system.