Dip-shaped AlGaN/AlN quantum well structures with high TE-polarized optical gain

Optical gain characteristics of dip-shaped AlGaN/AlN quantum well (QW) structures in deep-ultraviolet (UV) spectral region were investigated using non-Markovian model with the many-body effect. For a high Al composition of 0.85, the conventional AlGaN/AlN QW structure shows that TM-polarization is dominant. On the other hand, with the inclusion of the lower bandgap AlGaN layer, the polarization property changes from TM-polarization to TE-polarization with a small wavelength change.