Carrier heating in InGaAsP laser amplifiers due to two-photon absorption

Abstract
The carrier dynamics in an InGaAsP quantum‐well laser amplifier excited by an ultrashort optical pulse is investigated experimentally as well as theoretically. For operation in the absorption region, a transition from pump induced cooling to pump induced heating of the carriers is observed for increasing pump pulse energy and is attributed to the generation of hot carriers through two‐photon absorption. The results further support the interpretation of the carrier dynamics in the perturbative regime.