LOW-POWER NON-LINEAR OPTICAL PHENOMENA IN DOPING SUPERLATTICES.

We report calculations of the absorption coefficient and the refractive index of semiconductors with doping superlattices as a function of the excitation level. Results for two examples using GaAs and InAs as host materials are presented. We find that the optical properties of these systems are strongly dependent on the light intensities owing to the dependence of the built-in electric fields on the density of photoexcited charge carriers and to their long recombination lifetimes. We discuss possible applications of doping superlattices as nonlinear optical devices.