Interdiffusion-induced polarization-independent optical gain of an InGaAs-InP quantum-well with carrier effects

A theoretical study of the polarization-independent optical gain using group V sublattice interdiffusion in InGaAs-InP quantum wells (QW's) is presented here. The reverse bias and carrier effects on the subband structures, transition energy, and optical gain of the interdiffused QW are discussed. The interdiffused QW structures are optimized in terms of their subband structure, carrier density, structural parameters, and properties of optical gain spectra, The results show that an optimized interdiffused QW structure can produce polarization-independent optical gain over a range of operation wavelengths around 1.5 mu m, although the differential gain and linewidth enhancement factor are slightly degraded. The required tensile strain for the polarization-independent optical properties of a lattice-matched QW structure may be generated using interdiffusion, These results suggest that polarization-independent optical devices can be fabricated using interdiffusion in a lattice-matched InGaAsP QW structure.