Investigation on the Switching Transient of GaAs PCSS Operating in the Transition From Linear to Nonlinear Mode

The switching transient of gallium arsenide photoconductive semiconductor switch (GaAs PCSS) undergoing the transition from linear mode to nonlinear mode is investigated based on a "two-channel" model. Excellent agreement between the simulated and the experimental output waveforms is achieved first in the study of this transitional mode. The numerical results have revealed that a competitive relationship exists between the switching and nonswitched channels of the PCSS, and the formation and evolution of avalanche domains boost the nonlinear mode developing in the switching channel to win out from the linear mode dominated by the nonswitched channel. Based on the numerical model, the effects of the cross section of current channel on the output characteristics are well analyzed and discussed, which have also been demonstrated experimentally.