Peculiar work mode of GaAs PCSSs at high bias electric-field

The photocurrent waveform from the semi-insulating GaAs Photoconductive semiconductor switch (PCSS) when using different trigger laser energy and electric field has been tested. The peak value of current is in direct proportion to the work voltage at higher laser energy and lower storage capacitor shown different switch characterizes from the existing two work modes. A photograph of the switch has been taken using a high speed camera when it discharged and no filament was founded. The results were discussed from the generating and recombination process of the carrier and a peculiar work mode called quasi-linear in this letter of high power GaAs PCSSs was mentioned. Tests have been fulfilled to learn the requirement of laser energy to achieve this work mode at different terms. Because there is no filament in the switch quasi-linear mode means long lifetime. It has been shown in a typical example of the quasi-linear mode in which a hold-off voltage of 11.0 kV, current of 2.5 kA, FWHM of ~3 ns, repetition of 50 Hz and continues test time of more than two hours has been achieved.