Polarization of eigenmodes and the effect on the anisotropic gain in laser structures on nonpolar and semipolar GaN

The resonator orientation of InGaN-based lasers on semipolar planes influences the optical polarization and the gain. We present gain measurements of semipolar (1122) laser structures with differently oriented resonators and for various polarization states. The optical polarization state and the thresholds for lasers on different semipolar and nonpolar orientations are compared. The experimental results are accompanied by numerical calculations of the material gain as well as investigation of the surface morphology and resulting waveguide losses in dependence of the crystal orientation.