THEORETICAL-ANALYSIS OF STRAINED-LAYER INGAAS/GAAS QUANTUM-WELL LASERS WITH GAIN SUPPRESSION AND VALENCE-BAND MIXING

Linear gain, gain suppression, and L-I characteristics of strained-layer InGaAs/GaAs quantum-well laser are studied theoretically, taking into account valence-band mixing effects with biaxial compressive strain. It is found that the biaxial compressive strain substantially alters subband structure by pushing the light-hold subband bands into higher-energy states. It also alters the optical gain of a quantum-well laser. In particular, the biaxially compressed strained-layer InGaAs/GaAs quantum well shows a pronounced preference for TE polarization over TM polarization and the higher optical gain than does a typical GaAs/AlGaAs quantum well. The L-I characteristics are obtained self-consistently from the rate equations for the carrier and the photon densities and the calculated L-I curve shows reasonable agreement with the experimental data.