Optimized Design Of MEMS-Based Lidar Transceiver Optical System

MEMS-based lidar with high accuracy,small size and low cost has been in increasing demand in various fields such as military and civil applications,which also poses new challenges to the corresponding optical design field and other complementary fields.In this paper,based on the transversal project of laser 3D imaging sensor system in laboratory,the optimized design of MEMS-based LIDAR transceiver optical system is investigated to support the performance improvement of LIDAR,and the main research work is as follows:Firstly,by investigating the research status of LIDAR transceiver optical system at home and abroad,we select the core devices and the basic model of transceiver optical system,and propose the design index,and develop the design scheme of transceiver optical system;then we design and analyze the transmitting optical system by optical design software Code V and Light Tools,combined with the basic optical theory,including the collimation optical system for collimation shaping Then,the optical design software Code V and Light Tools are used to design and analyze the transmitting optical system,including the collimation optical system for collimation shaping,the angle expansion optical system for expanding the scanning field of view,and the temperature adaptation analysis according to the working environment of the system after the design is completed;secondly,the optical design software Code V is used to design the receiving optical system and the temperature adaptation analysis according to the basic optical theory;finally,the supporting optical structure is designed for the designed transmitting and receiving optical system,including Finally,the transmitting and receiving optical system is designed with respect to the supporting optical structure,including the mirror barrel,the spacer,the connecting parts and the whole housing,and the overall optical structure is analyzed statically,modally and temperature-adapted,and other reliability analyses are performed.The emission optical system designed in this article has a working distance of100 m,a wavelength of 905 nm,and a maximum beam divergence angle of 2.10 mrad in a working environment of-10 ℃～40 ℃ × 1.88 mrad,with a minimum scanning field of view angle of 31.82 °,achieving nearly twice the expansion of MEMS scanning field of view angle.The optical system transmittance is 70.8%,which meets the design requirements;The designed receiving optical system has a working distance greater than 100 m and a field of view of 30 °.In a working environment of-10 ℃～40 ℃,the maximum receiving spot distribution radius is 1.148 mm,which is smaller than the photosensitive surface radius of the APD detector(1.5mm).The optical system transmittance is 69.8%,meeting the design specifications;The natural frequency of the overall optical and mechanical structure is 1275.1Hz,which will not resonate with the environment(the natural frequency of the environment is 300Hz).The maximum stress generated under overload conditions is 17.767 Mpa,which is less than the allowable stress of the material.In the working environment of-10 ℃～40 ℃,the maximum thermal deformation generated by the mirror group is 0.0050098 mm,which has minimal impact on the optical system.The analysis results show that the overall optical and mechanical structure is relatively stable and the design is reasonable.