Edge artifact improvement in multipixel LiDAR imaging via tailored optical beam shaping

In push-broom topographic mapping using area-array lidar, due to the Gaussian energy distribution of the laser beam leads to edge information loss and black borders in the resulting images. To mitigate these issues, the system employs a microlens array to expand the beam's field angle and a double-layer lens for collimating the output, forming a “U”-shaped planar laser beam. The “U"-shaped planar laser beam exhibits Lambertian reflection when interacting with the target surface. Subsequently, the collimated echo beam scatters from the target surface, passes through a double-mirror system for optical path folding and pointing calibration, and ultimately produces a square spot with high uniformity through a double-stage microlens array and Fourier lens homogenization system. Mathematical models for both the output and receiving optical paths are formulated, scrutinized, and validated through imaging experiments. The outcomes demonstrate a notable enhancement in edge information detection efficiency by approximately 22.9 % within the proposed system, leading to the acquisition of more comprehensive target information and significantly elevating the imaging quality of multipixel area-array lidar.