DRIVE CIRCUIT DESIGN FOR AEROSPACE SEMICONDUCTOR LASER BASED ON SiC DEVICE

Drive circuits, which are the core part of semiconductor lasers, are crucial to the field of aerospace science and technology, such as laser guidance and Light Detection and Ranging. Given the extremely high quantum efficiency of semiconductor lasers, changes in current easily affect the stability of the output power of semiconductor lasers, which is not conducive to their safe use. Given that the output wavelength and power of semiconductor lasers are considerably changed in the case of even minor changes in the drive current, the working characteristics of semiconductor lasers were analyzed in this study, and the drive circuit design requirements of aerospace semiconductor lasers were obtained. Through circuit simulation, a four-phase interleaved parallel buck converter was established as the main power circuit topology of the semiconductor laser, followed by modeling analysis and compensation network design for the converter through the state space averaging method. Then, the drive circuit was controlled through the average current control method combining the all- Silicon Carbide scheme, and the prototype drive circuit was experimentally verified. Results demonstrate that the drive circuit of the aerospace semiconductor laser designed with a four-phase interleaved parallel buck converter can reduce the ripple coefficient of the output current from 0.244 to 0.015, effectively improve the power system stability, and remarkably improve the switching frequency and power density of the semiconductor laser. The proposed algorithm provides evidence for the optimization and performance evaluation of semiconductor laser drivers for aerospace applications. Keywords: Semiconductor laser, drive circuit, Silicon Carbide, four-phase buck, interleaving parallel.