Resonant coupled-cavity effects in VCSELs with annular ring contacts

摘要

The role of metal apertures in the mechanism of lateral mode confinement in vertical-cavity surface-emitting lasers (VCSELs) is clarified by means of a detailed effective-frequency-method analysis of an oxide-confined VCSEL structure with the radius of the oxide window exceeding that of the metal aperture. Ring metal contact layer on top of the VCSEL structure is shown to be able to change the conditions for the lateral waveguiding in VCSELs by significantly modifying the local resonant properties of the VCSEL cavity. The resonant effects are demonstrated in the longitudinal coupled-cavity system consisting of the designed laser cavity, determined by the lower and top DBRs, and a very short cavity formed by the top DBR and semiconductor-metal interface. The conditions for higher-order lateral mode suppression using metal apertures are established.