MODELING OF GAIN, DIFFERENTIAL GAIN, INDEX CHANGE, AND LINEWIDTH ENHANCEMENT FACTOR FOR STRAIN-COMPENSATED QWS

The gain, differential gain, index change, and linewidth enhancement f actor for strain-compensated InGaAs-GaAsP-InGaP quantum wells (QW's) a re modeled. The model we have developed builds upon the model-solid th eory for determining the band offsets, the k . p method for calculatin g the matrix elements of dipole moment, and the density matrix approac h for computing the complex susceptibility of strain compensated QW's. We also incorporate bandgap renormalization. The calculated results b ased on the model are consistent with available experimental results i n the literature. It is shown that InGaAs-GaAsP-InGaP strain-compensat ed QW's could offer much higher gain, higher differential gain, and lo wer linewidth enhancement factor than AlGaAs-GaAs conventionally compr essively strained QW's, but more because of its larger band offset tha n anything else.