Subnanosecond Operation of a Microstrip Optoelectronic Switch

Experimental results and a theoretical model concerning optoelectronic switches are reported. These devices mainly consists in a microstrip line, deposited on a high resistivity semiconductor. The upper strip has a break which can be illuminated by a laser pulse. The latter generates an electron hole plasma of high density near the semiconductor surface allowing the signal transmission accross the gap. In order to verify some assumptions allowing further simplification to describe the operation of such devices, a numerical model has been derived. It leads to a simpler analytical model in which the inductive phenomena and the propagation process along the active part of the device are taken into account. These models have been compared to experimental results in the nanosecond range and allow to forecast the performances in the picosecond range.