Preliminary experiments with large optical absorption depth, high field, linear, photoconductive switches

Abstract

High electric field geometries for high power, photoconductive switches made possible by employing above bandgap photons and interbandgap dopants / defects are being investigated for compact pulse power systems. The high field, long absorption depth package reduces the required linear mode, optical closure energy and also reduces the conduction current density through the active material and at the contacts. In addition, the long absorption depth package increases the area available for thermal management and in concert with the reduced current density should increase the lifetime of the switch. This paper describes the design of the experimental test system, including high frequency current and voltage diagnostics, pulse charge system, and optical closure energy distribution system. The design and fabrication of the high-field package are presented.