High power light activated semiconductor switches with sub-nanosecond rise times

The authors present a summary of results from experiments with large GaAs, InP, and silicon photoconductive semiconductor switches (PCSSs). Linear and high-gain (lock-on) switching modes are described. Individual PCSSs were used to switch voltages as high as 120 kV and currents as high as 4.2 kA, and risetimes as fast as 200 ps in the linear mode and 600 ps in the initiation of lock-on were produced. The high gain switching mode is important to applications which must be compact or operate at high repetition rates. The highest power switched to date with a pulsed semiconductor laser diode array (100 W) is 40 MW. The potential development of these switches for future applications is also discussed.<>