Demonstration of III-nitride vertical-cavity surface-emitting lasers with a topside dielectric curved mirror

We report long cavity (65 lambda) GaN-based vertical-cavity surface-emitting lasers (VCSELs) with a topside dielectric concave mirror, an ion implanted current aperture, and a bottomside nanoporous GaN distributed Bragg reflector. Under pulsed operation, a VCSEL with a 10 mu m aperture and a curved mirror with a radius of curvature of 120 mu m had a threshold current density of 14 kA cm-2, and a maximum output power of 370 mu W for a lasing mode at 404.5 nm. The longitudinal performance has a side-mode suppression ratio of 30 dB up to a current density of approximately 40 kA cm-2. Multiple transverse mode profiles are observed across several devices.