Laser driver switching 20 A with 2 ns pulse width using GaN

A GaN-HEMT-based circuit is presented capable of switching 20 A of current with less than about 0.5 ns rise and fall time. This demonstrates the potential of GaN transistors for high-current switching applications, even if breakdown voltage requirements are low. The current driver is used to realize an optical pulse picker generating 10 ps optical pulses of more than 30 W with a variable repetition rate between 1 kHz and 100 MHz.