HIGH-POWER CONVERSION EFFICIENCIES AND SCALING ISSUES FOR MULTIMODE VERTICAL-CAVITY TOP-SURFACE-EMITTING LASERS

We report advances in the power conversion efficiencies of vertical-ca vity top-surface-emitting lasers defined by proton implantation. Effic iencies as high as 13.4% and 15.8% have been obtained for single-mode and multimode operation, respectively. Scaling issues are addressed in cluding the size dependence of threshold current, series resistance, l asing output power, and power conversion efficiency. We find that devi ces between 15 mum and 25 mum diameters show the highest power convers ion efficiency due to the threshold current not scaling with the condu ctance and output power. Device geometries with contact apertures both equal to and less than (overlapping) the active region diameter were investigated.