Gain-loss model for the dependence of the stimulated-emission transition in AlGaAs-GaAs quantum well heterostructures on photoexcitation geometry

The gain-loss laser oscillation condition is applied to photoexcitation geometries in which phonon-assisted laser operation is observed in AlGaAs-GaAs quantum well heterostructures (QWHs). The model is found to agree with a variety of experimental conditions in which cavity size, photoexcitation spot size, and mirror reflectivity are varied. Also, it serves to indicate further how others might have failed to observe phonon-assisted laser operation in QWHs and how photoexcitation geometries can be varied to verify these results.