<title>Self-consistent 2D simulations of filament propagation in photoconducting switches</title>

Abstract

We present simulations of time-dependent filament propagation in laser-triggered GaAs photoswitches. Unlike previous modeling, our calculations are self.consistent in 2-D axisymmetric (r-z) geometry. Realistic electron and hole mobilities as well as field dependent impact ionization are included. We observe filament propagation with speeds Up108-109 cm/s. much larger than the saturated carrier drift velocity, ut=4Olcm/s. The self-consistently determined filament radius and carrier number density are typically Rf=20..6Ojim and nf1O17.1O'8 cm3 respectively. Results are presented for filament propagation in systems with both uniform and non unifonn profiles of background carrier density and electric field.