Modeling of gain, differential gain, index change, and linewidth enhancement factor for strain-compensated QWs

The gain, differential gain, index change, and linewidth enhancement factor for strain-compensated InGaAs-GaAsP-InGaP quantum wells (QWs) are modeled. The model we have developed builds upon the model-solid theory for determining the band offsets, the k/spl middot/p method for calculating the matrix elements of dipole moment, and the density matrix approach for computing the complex susceptibility of strain compensated QWs. We also incorporate bandgap renormalization. The calculated results based on the model are consistent with available experimental results in the literature. It is shown that InGaAs-GaAsP-InGaP strain-compensated QWs could offer much higher gain, higher differential gain, and lower linewidth enhancement factor than AlGaAs-GaAs conventionally compressively strained QWs, but more because of its larger hand offset than anything else.