Role Of Electron-Hole Pair Correlations In Gain And Stimulated-Emission Of Blue-Green Semiconductor-Lasers

Spectroscopic work is reviewed that focuses on the microscopic mechanism of gain in ZnSe-based quantum well (QW) lasers, under optical and electrical injection, respectively. In particular, the lasing process in optically pumped ZnCdSe/ZnSe QW lasers at cryogenic temperatures is shown to be an entirely excitonic process. This conclusion is supported by results from resonant pumping experiments and femtosecond pump-probe measurements. Recent studies on the room temperature diode lasers show that electron-hole pairwise Coulomb correlations remain relevant in this case as well.