Influence of anti-phase surface relief structure on optical mode and laser output power for 450 nm GaN-based VCSELs


 For GaN-based vertical-cavity surface-emitting lasers (VCSELs), single-mode output and high power are difficult to be achieved simultaneously. In this report, we propose increasing the output power while taking the optical field into account by engineering the anti-phase surface relief structure and current aperture size for GaN-based VCSELs. We find that the proposed anti-phase surface relief structure helps to get Gaussian-shaped near-field and far-field patterns for VCSELs. However, such structure suffers from mirror loss and causes decreased laser power. Hence, the current injection aperture size has to be reduced so that the overlap level between the carrier profile and the anti-phase surface relief region can be decreased. Therefore, VCSEL structure with enhanced laser power and dominating fundamental laser mode can be finally designed.