Stable single-mode operation of VCSELs with a mode selective aperture

Abstract

We have developed single-mode vertical-cavity surface-emitting laser (VCSELs) with a mode selective aperture (MSA) in the DBR mirror that exhibits a high-order transverse-mode filtering effect. The VCSELs with an MSA were fabricated using standard intracavity-contacted VCSEL processes without any additional steps resulting from the simultaneous formation of the MSA and current aperture via a single-step oxidation. The VCSELs fabricated with a current aperture and MSA diameter of 5 and 7 mu m, respectively, exhibited a stable single-mode operation with a side mode suppression ratio of over 35 dB and a divergence angle below 10 degrees for the entire drive current range.