OPTICAL GAIN OF CDZNSE ZNSE QUANTUM-WELL LASERS

Polarization-dependent optical gain of recently demonstrated CdZnSe/ZnSe quantum well lasers is calculated for the first time. Our analysis is based on the multiband effective mass theory (k.p theory) and the density matrix formalism with intraband relaxation taken into account. It is shown theoretically that the TE mode gain is significantly larger than the TM mode gain for a wide range of carrier density. Comparison of the room-temperature TE mode gain of CdZnSe/ZnSe quantum well with that of GaAs/AlGaAs quantum well gives disappointing results for the II-VI semiconductor lasers. It is expected that the optical gain of the ZnSe-based semiconductor lasers would be substantially smaller than the optical gain of the GaAs-based semiconductor lasers for a same quantum well width and carrier density.