Simultaneous Enhancement of Scanning Area and Imaging Speed for a MEMS Mirror Based High Resolution LiDAR

Abstract

High speed imaging with improved resolution and wide area scanning are the ultimate targets for designing a MEMS mirror based LiDAR. Simultaneous improvements of above parameters are critical and yet pose design tradeoff among system complexity, cost and compatibility. Here, we propose a high resolution LiDAR for wide area scanning with improved frame rate by allowing minimum design constrains. Extended area scanning is achieved by simplified transmitter design with off-the-shelf low cost optics such as a beam splitter cube and a plane mirror. In addition, an effective scanning strategy is applied to improve the imaging speed for the extended coverage area, which involves sub-pixel imaging of selectively and sequentially shined target areas. Then, a high resolution image can be reconstructed after merging all the sub-pixel values. The proposed architecture is experimentally demonstrated to reconstruct a high resolution image of 1020 x 500 pixels at the fast refresh rate of 20 fps in extended FoV 52 degrees x 26 degrees. The system is also characterized in terms of linearity of extended optical angles, intensity distribution of light beam profile at several angular positions, and quality of scanned objects in the high resolution reconstructed image.