Characteristics of the GaAs Photoconductive Semiconductor Switch Operated in Linear-Alike Mode

The photoconductive semiconductor switches (PCSSs) have two operating modes, i.e., linear mode and nonlinear mode (also “lock-on” mode). The low bias voltage and high trigger energy are needed when the switch is operated in a linear mode, but the high bias voltage and low trigger energy are needed when the switch is operated in a nonlinear mode. When the GaAs PCSS is triggered under the condition of the low bias voltage and low trigger energy, the on-state characteristic of the switch is similar to that in the linear mode but different from the nonlinear mode. We refer to this mode as “linear-alike mode.” In this paper, a research on the GaAs PCSS triggered by a laser diode in different low bias voltages is reported. The performance of linear-alike mode is analyzed and an equation used to calculate the on-state current is put forward, on the basis of which a method to measure the ionization rate is presented.