Light scattering in high-dislocation-density GaN

Light scattering by edge dislocations and the resulting loss coefficient have been modeled for GaN layers. Phase-front deformation caused by the refractive-index variation in the dislocation’s strain field has been considered and the resulting scattering loss calculated. We show that the high dislocation densities observed in recent GaN layers can result in significant large loss coefficients. The present work also offers some insights for improved lasers.