The effect of thickness of delta-strained Layers in the design of polarization-insensitive semiconductor optical amplifiers

We have analyzed the effect of thickness of delta (δ)-strained layer in the design of polarization insensitive semiconductor optical amplifiers. We considered a system consisting of a single quantum well (QW) with several different locations and varying thicknesses of δ layer. For its analysis, we used the self-consistent approach of solving the Poisson, Schrödinger, and 4 × 4 Lüttinger-Kohn equations. The many-body effects of bandgap renormalization, Coulombic scattering interactions, and a non-Markovian distribution were all included in the model. We have found that up to eight monolayers produce very good polarization insensitivity (<1 dB) provided that the δ layer is properly positioned inside QW. For a given thickness of δ layer, we also provide the location inside QW which gives the best polarization insensitivity.