Kilowatt Laser Driver with 120 A, sub-10 nanosecond pulses in < 3 cm2 using an GaN FET

Inhalt:
Lidar time-of-flight distance measurement has become the primary means of high-speed, accurate mapping of 3-D space. A primary application for lidar is for navigation and obstacle avoidance in real-time Advanced Driver Assistance System (ADAS) and autonomous vehicle navigation. The lidar pulsed laser transmitter is a key lidar subsystem. The transmitter must generate high power optical pulses of short duration of less than 10 ns. For a 10 s vehicle sense and response time, a range of 300 m is required, which in turn requires high peak laser power. This work describes a laser driver using a single commercial GaN FET to achieve current pulses into a laser diode of >150 A peak for a peak laser input power of > 4 kW, with a duration < 8 ns. The area occupied by the driver and laser is < 1.3 cm2.