Bipolar Pulsewidth Modulation-Based Control Technology Research for Optical Phased Array LiDAR

Silicon-based optical phased array (OPA) can achieve full solid-state beam steering, which is a promising solution for next-generation light detection and ranging (LiDAR). As OPA research progresses, OPA LiDAR is approaching readiness for industrial application. However, most of the OPAs are mainly configured with digital-to-analog converters (DACs), which suffer from high-power consumption, low efficiency, high cost, and complex circuitry, especially for thermal-optical OPAs. Here, we design a control system for thermal-optical OPA based on bipolar pulsewidth modulation (BPWM). Compared with a DAC-based solution, our system maintains comparable performance in terms of spot quality, detection performance, etc. Additionally, the heat load on the OPA chip is effectively reduced, the average power consumption of the system is reduced by 74.4%, the average operating efficiency of the driver module improved to a factor of 3.96 of the original one, and the device cost has also been significantly reduced. Finally, an OPA LiDAR prototype is constructed based on our pulsewidth modulation (PWM) control system, which is able to obtain a clear 4-D point cloud. To our best knowledge, this is the first demonstration of point cloud imaging by the OPA LiDAR system with PWM control. This work facilitates the commercialization of OPA LiDAR.