High Power Nanosecond Pulse Laser Driver Using an GaN FET

Lidar optical time-of-flight measurement has become an important method of accurate determination of distance to remote targets. Some lidar applications, such as 3-D continuous mapping for autonomous vehicles, demand both accuracy and a high measurement sample rate. To meet these demands, the optical transmitter must be able to generate high power pulses of very short duration, typically accomplished by driving a laser diode with very short, high current pulses. This paper presents a laser diode driver which uses gallium nitride power FETs to generate current pulses with peak values of > 35 A and pulse widths < 4 ns with commercially available components and conventional printed circuit board technology. Finally, recent improvements will show that pulse widths <2 ns are possible.