Excitonic optical bistability in n-type-doped semiconductors

Abstract

A resonant monochromatic pump laser generates coherent excitons in an n-type-doped semiconductor. Both exciton–exciton and exciton–donor interactions come into play. The former interaction can give rise to the appearance of optical bistability, which is heavily influenced by the latter one. When optical bistability occurs at a fixed laser frequency both its holding intensity and hysteresis-loop size are shown to decrease with increasing donor concentration. Two possibilities are suggested for experimentally determinng one of the two parameters of the system, the exciton–donor coupling constant or the donor concentration if the other is known.