Recovery of high field GaAs photoconductive semiconductor switches

The authors discuss the recovery of GaAs PCSS (photoconductive semiconductor switches) after they are triggered into a high gain switching mode called lock-on. Fast recovery of GaAs switches after high field switching is of particular interest for high repetition rate applications where it is difficult to provide the large optical trigger energy required for switches operating at low fields. Three categories of circuits for inducing fast recovery after lock-on by temporarily reducing the field across the switch are examined. Measurements of recovery times from 35-80 ns, multiple monopolar and bipolar bursts at 5-40 MHz, and hold-off fields ranging from 5-44 kV/cm (corresponding to 15-66 kV across individual switches) are presented