1-kHz Repetitive Operation of Quenched High-Gain GaAs Photoconductive Semiconductor Switches at 8-nJ Excitation

To extend the avalanche multiplication mechanism of gallium arsenide (GaAs) photoconductive semiconductor switches (PCSS)for the generation of high-frequency electromagnetic waves, a quenched high-gain (HG) operation is presented with the utilization of smaller capacitance. Initially, HG operation of GaAs PCSS is demonstrated by optical excitation energy as low as 6 nanojoules (nJ). Furthermore, it is shown that the quenched HG operation can be achieved at 8 nJ with a capacitance of 0.25 pF. Different repetition rates up to 1 kHz are utilized to investigate the performances of GaAs PCSS biased at 61.8 kV/cm. It is verified that the carriers' multiplication level can be kept during the quenched HG operation. Good repeatability of switching predicts that the stable quenched HG operation at higher repetition rate could serve as the basis for high- power terahertz emission.