High-power GaAS photoconductive semiconductor switches triggered by laser pulse with different beam profile

High-power photo conductive semiconductor switches with a gap of 12 mm were fabricated from semi-insulating GaAs, in which carbon acceptor impurity was compensated by deep EL2 donor defect, resulting in very large dark resistivity. Triggered by laser pulse with different optical energy at wavelength of 1064 nm and 532 nm, photoconductivity tests of the PCSS at different bias voltage are underway. In order to understand the influence of laser beam profile on photoconductivity of the PCSS, several types of laser beam profile will be used, such as illumination throughout the surface of the PCSS, 1-mm-wide strip illumination spanning the electrode gap, 1-mm-wide strip illumination parallel to the electrode, and laser spot. 1-mm-wide strip illumination parallel to the electrode will be respectively located at the center of the gap, near the cathode and near the anode. An overview of the PCSS characteristics and initial experimental results will be presented.