Electric Field Measurements In Photoconductive GaAs Switches

The Frum-Keldysh effect has been used to measure the electric field distribution in a photoconductive gallium arsenide switch. The results indicate the build-up of electric fields at the anode during lock-on and subsequent dielectric breakdown leading to current filamentation. The diagnostic technique, which has a temporal resolution given by the probe laser, can be extended to provide information on the carrier density distribution and the temperature distribution in the gallium arsenide switch.