PHOTOCONDUCTNITY QUENCHING IN A GaAs OPENING SWITCH PULSED POWER SYSTEM E. E. Funk and Chi

The use of a GaAs photoconductive closing and opening switch in an inductive energy storage system has, in the past, required a custom built laser with optical pulse shaping. We now describe a system which may be operated by a simple, Q-switched laser pulse. We have designed a high impedance (500-Q) system which provides a switch conduction time which is sustained longer than the laser pulse. Furthermore we have demonstrated that at high voltages the switch exhibits fast quenching of conductivity resulting in opening times of less than 20-ns after sustained conduction. This fast opening action has allowed us to achieve a power gain of up to 8.9 and switched out voltages as high as 7-kV.