Extended field-of-view scanning in LiDAR systems using computer-generated holography-based spatial light modulator

Abstract

A method is proposed for realizing extended field-of-view (FOV) scanning in light detection and ranging (LiDAR) systems utilizing computer-generated holography, a spatial light modulator (SLM), and an eye piece. In the proposed approach, an SLM driven by appropriately-designed computer-generated holograms (CGHs) is used to collimate the incoming rays and produce a large field of view (FOV). Five FOVs are considered for illustration purposes: 0°, -5°, -10°, -15°, and -20° For each FOV, the necessary CGH is determined by optimizing the “Binary 1″ surface in Zemax simulations and then processing the resulting phase by a modulo-2π operation. The feasibility of the proposed method is demonstrated using an experimental telescope system. The results show that the FOVs generated by the system deviate by no more than 0.566° from the target values. Moreover, the focus spot maintains a size of approximately 3 mm at two different observation planes located at 73 cm and 198 cm from the eyepiece, respectively. In other words, the system not only provides an extended FOV scanning range, but also delivers an excellent collimation performance. Overall, the results thus confirm the potential of the proposed method for large FOV scanning in practical LiDAR systems.