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

Abstract

We report long cavity (65λ) 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 μm aperture and a curved mirror with a radius of curvature of 120 μm had a threshold current density of 14 kA cm−2, and a maximum output power of 370 μW 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.