Semiconductor lasers from photoconductive switch filaments

At the 8/sup th/ Pulsed Power Conference (1991), this group reported the first images of current filaments in high gain photoconductive semiconductor switches (PCSS). Since that time many properties of the current filaments have been reported, including the ability to control the location, shape, and timing of the filaments with an optical trigger. Recently, we have invented a new class of semiconductor laser, using current filaments as the active region. We have fabricated and tested current filament semiconductor lasers (CFSL) producing 75 nJ of 890 nm radiation in 1.5 ns (50 W peak), approximately ten times more energy than conventional (injection-pumped) semiconductor lasers (CSL) in comparable pulse lengths.