Model calculation of the laser-semiconductor interaction in subpicosecond regime

Abstract

We develop a model calculation to investigate the interaction of a subpicosecond laser pulse with a direct-gap semiconductor. In this problem, carrier distributions are extremely far from equilibrium and nonequilibrium LO phonons are generated at the center of the Brillouin zone. We solve numerically a system of three transport equations, namely one for the conduction band, one for the valence band and one for the LO phonons. Contrary to all previous work, we do not assume that carrier distributions are nondegenerate so that we can investigate the following problems: (a) conditions of internal thermalization in degenerate nonequilibrium plasma (thermalization time, influence of screening on the energy-loss rate, formation of nonequilibrium LO phonons) and (b) absorption saturation and transmission of the pumplaser pulse. © 1986.