Low-temperature absorption spectrum in GaAs in the presence of optical pumping

Abstract

Measurements of the absorption spectra of high purity GaAs in the presence of intense uniform optical pumping are described. With increasing excitation the resonant exciton absorption broadens and disappears, but the enhancement of the above bandgap absorption persists up to the highest intensities used. At these intensities the data can be fit by a calculation which includes band-gap renormalization and carrier heating resulting from intense optical pumping.