Single-mode vertical-cavity-surface-emitting-laser (VCSEL) with ring shaped microcavity and low divergence angle performance

We demonstrate 850 nm single-mode vertical-cavity-surface-emitting-lasers (VCSELs) with ring-shaped microcavity. Compared with the reported single-mode VCSELs, larger area of light-emitting aperture, smaller divergence angle of output beam, and lower resistance, have been achieved by our structure.