Modeling of optical spectra for characterization of multiquantum well InGaAsP-based lasers

The features observed in luminescence and photoreflectance spectra are interpreted by detailed modeling of the electronic states, absorption and luminescence of the active region. The electronic states for the full active region (quantum wells together with separate confinement layers) are calculated using an eight band k (DOT) p model. The axial approximation, tested to be sufficiently accurate, is used to reduce the computational burden. The Poisson equation is included self consistently for the optically pumped case. Analysis of the photoreflectance spectra includes incorporation of an electric field across the active region. Good agreement for the positions of the features and their trends with compositional variables verifies the accuracy of the model. Higher lying transitions involve electron levels above the barrier energy which can be confined to the region of the wells by the self consistent field for pumped material.