THEORETICAL CALCULATION OF OPTICAL GAIN AND THRESHOLD CURRENT-DENSITY IN STRAINED IN1-XGAXAS/INP QUANTUM-WELL LASERS USING STRAIN-DEPENDENT CONDUCTION-BAND AND VALENCE-BAND STRUCTURES

We theoretically calculate the optical gain of In1-xGaxAs/InGaAsP strained quantum wells on (001) InP substrates based on strain-dependent conduction-band and valence-band structures. Using the calculated gain, we estimate threshold current density of the strained quantum-well lasers. We show that both biaxial compressive and tensile strains can lower the threshold current density by 1/2-1/3, and clarify the mechanism for the reduction. (C) 1994 John Wiley and Sons. Inc.