Gain Anisotropy Analysis in Green Semipolar InGaN Quantum Wells with Inhomogeneous Broadening

Polarization switching phenomena in semipolar ($11\bar{2}2$)-oriented InGaN quantum wells (QWs) were theoretically investigated by a newly formulated model considering the effect of In compositional fluctuation. The theoretical model successfully reproduced the reported polarization switching phenomena for both the emission wavelength and the excitation density in blue-green ($11\bar{2}2$) QWs, and this showed the importance of inhomogeneous broadening effects to understand polarization properties of semipolar quantum wells. Then, the model was applied for pure-green ($11\bar{2}2$) QWs, and we predicted that optical polarization was kept in the [$11\bar{2}\bar{3}$] direction up to the carrier density high enough to create population inversion in such long-wavelength QWs. These results support the possibility for semipolar-oriented pure green InGaN laser diodes with cleaved facet cavity mirrors.