Analysis of QW with strained thin layers for polarization insensitive optical amplifiers

A practical approach to achieve the polarization insensitive optical gain at 1.55 μm with quantum well (QW) in which thin and highly tensile strained layers are embedded is numerically investigated. The precise band structures and the optical gain characteristics of the structure are calculated. Comparing with the results obtained from the tight-binding model, we concluded that the k · p method based on the envelop function approximation is still valid for such complicated structures like δ-strained quantum wells.