Design and manufacturing of a highly integrated optical module for Tianwen-1 probe's landing LiDAR. (February 2023)

• Record Type: Journal Article
• Authors: Zhang, Yunfang; Zhu, Feihu; Zheng, Yan; Wang, Li; Guo, Shaogang; Hua, Baocheng; Li, Lin; Chen, Jianfeng; Liu, Yang; Cao, Zhongxiang; Liu, Qihai; Zhang, Donglai; Hu, Yanxu; Hong, Shuai
• Is Part Of: Optics and lasers in engineering. Volume 161(2023)
• Publication Date: 2023-02
• Subjects: Laser radar (LiDAR) -- Optical module -- Design of the optical system -- MEMS mirror; SNR signal-to-noise ratio -- LiDAR laser radar -- MEMS micro-electromechanical system -- FOV field of view; Lasers in engineering -- Periodicals; Optical measurements -- Periodicals; Optics -- Periodicals; Lasers en ingénierie -- Périodiques; Mesures optiques -- Périodiques; Optique -- Périodiques; 621.36605
• DOI: 10.1016/j.optlaseng.2022.107346
• Languages: English
• ISSNs: 0143-8166

Abstract

Highlights: The relationship between SNR and detection distance, scanning FOV is given. The impact response of the MEMS mirror was greatly reduced by a shock absorber. New optical design realizes long back working distance and small f number. A receiving module with strong resistance to solar interference is presented. The proposed module helped the Mars probe successfully determine a landing point. Abstract: In this study, a highly-integrated optical module based on micro-electromechanical system (MEMS) mirror, glass with low thermal expansion coefficient, a higher-order aspheric lens with high refractive index and two position-optimized optical filters is proposed. The Mars exploration mission requirements and the non-coaxial optical path of the optical module are discussed, while the relationship between the signal-to-noise ratio (SNR) and the detection distance, as well as between the scanning field of view(FOV)and the entrance pupil diameter, is given. The transmitting module consisting of a scanning device and angle magnifier has a temperature range of −20 °C to +40 °C, and a good reliability at 1800 g@4000 Hz. The receiving module using two ZnS lenses and two narrow-band filters with bandwidths of 22 and 10 nm has an f number of 0.55, a back working distance of 3.24 mm and a normalized energy collection efficiency at the edge of the FOV of 72.8%. The presented optical module has a Ø30°FOV, 120 m detection distance and 2 mrad angular resolution, and has been successfully applied to Tianwen-1 Probe's landing LiDAR.