Analysis of hot electron effects on intersubband Raman laser in modulation‐doped GaAs/AlGaAs coupled double quantum wells

Abstract

We present a simulation of hot electron effects on inter‐subband Raman laser (IRL) consisting of modulation‐doped n‐type GaAs/AlGaAs coupled double quantum wells (CDQWs) with high 2D electron density. A time evolution for occupation number and electron temperature in each subband as well as the number of lasing Stokes photons are calculated self‐consistently for the modelled IRL. It is shown that Raman gain exhibits a characteristic reduction synchronizing an increase of Stokes photon density as time is evolved in sub‐nanosecond range. Then a saturation feature of output power is expected. The energy relaxation due to the confined LO phonons and the interface modes gives rise to interesting change of electron temperature in subband 1 and subband 2 during the Raman lasing. The threshold optical pumping intensity is estimated to be 50 kW/cm2. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)