Effects of trigger light pulse on open performance of nonlinear photoconductive switch

A vertical GaAs PCSS is fabricated with a thickness of 0.6 mm and a gap of 3 mm, and the triggering experiment is carried out by semiconductor laser diode. Along with enhanced electric field, the output voltage increases linearly, the output waveform is similar to the laser waveform. When bias electric field exceeds the threshold, the output voltage increases rapidly, and the output voltage impulse is faster than the laser impulse which shows PCSS turns into nonlinear mode. Except for the bias voltage, PCSS turning into nonlinear mode is also associated with the speed and the energy of the trigger light pulse. Experiment indicates that the higher trigger energy is, the faster the rise-time is, the more likely the working mode of PCSS turns into nonlinear and the needing electric field is lower. But when bias electric field falls under the threshold (about 6 kV in this experiment), PCSS can not turn into nonlinear, even if the trigger light energy is enhanced.