Theoretical analysis of temperature sensitivity of differential gain in 1.55-μm InGaAsP-InP quantum-well lasers

We study the temperature sensitivity of the differential gain in InGaAsP-InP strained-layer (SL) quantum-well (QW) lasers operating at a wavelength of 1.55 μm. Electrostatic deformation in conduction-band and valence-band profiles is taken into account by solving Poisson's equation and the effective-mass equations for conduction and valence bands in a self-consistent manner. We demonstrate that electrostatic deformation in both band profiles plays a significant role in determining the temperature sensitivity of the differential gain in 1.55-μm InGaAsP-InP SL QW lasers. The physical mechanism for limiting the differential gain at elevated temperatures is also discussed.