Effect of Transition Mechanism of Photon-Induced Carriers on Time Jitter of GaAs Photoconductive Semiconductor Switches

To investigate the effect of photon-induced carrier transition mechanism on switch stability, the time jitters of 2-mm-gap gallium arsenide photoconductive semiconductor switches (GaAs PCSSs) are compared when triggered by lasers of two different wavelengths, i.e., 1064 and 532 nm. The time jitter model is proposed to clarify the synergy of the multiple adjustable macroparameters of trigger conditions. The carrier valley occupation rates with respect to bias electric field are simulated, where the influence of the microprocedures, i.e., carrier generation, carrier intervalley transition, and carrier transportation, is considered. Our experimental results illustrate that the time jitter of the GaAs PCSS exhibits a nonmonotonous behavior and obtains a local minimum at ~3 kV/cm for 1064 nm; however, it shows a monotonous decrease to a constant value at about 3 kV/cm for 532 nm. Our analysis indicates that the discrepancy in GaAs PCSS time jitter is attributed to the difference in the relative fluctuation of the carrier velocity affected by the carrier valley occupation rate. This article is of great significance in optimizing the stability of GaAs PCSS and pulse power system by adjusting the macroparameters in the time jitter model.