MEMS mirror based omnidirectional scanning for lidar optical systems

Abstract

Lidar 3D vision system is currently one of the most effective technical means for high-precision perception of three-dimensional image information of the surrounding environment. Microelectron-mechanical systems (MEMS) micromirror lidar has advantages of miniaturization, fast scanning speed, and relatively low price. The MEMS micromirror scanning method has become the best choice for laser scanning 3D image sensors. However, due to the small size of the MEMS micromirror, it can only scan a small angle range, which limits its industrial applications. In this paper, combined with MEMS micro-mirror spiral scanning form, we design a new type of omnidirectional optical system that can realize MEMS lidar omnidirectional scanning imaging. The overall optical system is composed of the catadioptric prism, the MEMS micromirror, and the compensation prism. The overall system can achieve 360° omnidirectional scanning imaging with a horizontal resolution of 0.1°; a vertical field view with a 0.5° resolution. The design results are analyzed by the optical design software (Zemax). The point diagram shows that the emitted light spots are circular and evenly distributed. The divergence angle is less than 1mrad, which can well meet the actual needs and solve the problems of solid-state, miniaturization, and omnidirectional scanning imaging of lidar.