Study of the frequency spectrum characteristics of ultra-fast photoconductive semiconductor switches

According to microwave and circuit theory, the transient response model is established after optically controlled photoconductive semiconductor switches (PCSSs) are radiated by ultra-short light pulse. A method for characterizing frequency spectrum characteristics of PCSSs is presented. A deep investigation of the effect of some structural and physical parameters on the frequency characteristics of PCSSs is made. The findings show that the carrier life and absorption coefficient of the photoconductive material for manufacturing the switches, the width of the gap, the pulse width of the incident light, the gap capacitance, lead and parasitical inductance have a great effect on the frequency characteristics of PCSSs. PCSSs have ability to produce THz electromagnetic radiation and can be as Teraherz radiation source.