Low threshold voltage vertical-cavity lasers fabricated by selective oxidation

Abstract

Novel vertical-cavity surface emitting lasers fabricated using selective oxidation to form a current aperture under a top monolithic distributed Bragg reflector mirror are reported. Large cross-sectional area lasers (259μm2) exhibit threshold current densities of 150A/cm2 per quantum well and record low threshold voltage of 1.33V. Smaller lasers (36μm2) possess threshold currents of 900μA with maximum output powers greater than 1mW. The record performance of these oxidised vertical-cavity lasers arises from the low mirror series resistance and very efficient current injection into the active region.