Study On Characteristics Of High Repetition Frequency Nonlinear Gaas Photoconductive Switches

With the development of pulse power technology,the pursuit of high-power pulse is an important objective,and achieving high-power,high-repetition frequency pulses is of great significance to national defense.In this letter,laser diode(LD)can replace the expensive and large laser system and can result in a compact triggering system at low costs.Transmission line energy storage.GaAs Photo-conductive Semiconductor Switches(GaAs PCSS)is triggered by repetitive frequency(kHz)LD.When GaAs PCSS works in avalanche multiplication quenching mode,the average output pulse width is about 2 ns,which is less than 23 ns of trigger light source pulse width,this mode is conducive to the realization of high repetition frequency mode of GaAs PCSS,and can also improve its working life.For the avalanche multiplication quenching phenomenon of GaAs PCSS,this paper establishes the equivalent circuit model of transmission line,then according to the law of charge conservation,and calculates the change of bias electric field of GaAs PCSS.When the bias electric field falls to about 7.5 kV/cm,the photoinduced charge domain quenching occurs in GaAs PCSS.The influence of bias voltage and LD trigger repetition frequency of GaAs PCSS on the output electric pulse is analyzed.When the bias voltage is 8 kV and the light trigger repetition frequency increases by 10 kH,the output electric pulse loses,that is,GaAs PCSS does not enter the high multiplier mode;when the light trigger repetition frequency is 10 kH,the higher the bias voltage,the less the loss of the output electric pulse.For the thermal accumulation of GaAs PCSS material,the unsteady heat conduction model is established,the thermal accumulation of GaAs PCSS at the instant of conduction is simulated and analyzed,the temperature rise of GaAs PCSS at different repetition frequencies is calculated,the critical frequency for GaAs PCSS to work normally is 9 kHz.