Demonstration of Nonpolar GaN-Based Vertical-Cavity Surface-Emitting Lasers

Electrically injected, single-longitudinal-mode nonpolar m -plane vertical-cavity surface-emitting lasers (VCSELs) are reported with a room-temperature lasing wavelength of 411.9 nm, a full width at half maximum (FWHM) of 0.25 nm, and a peak output power of 19.5 µW under pulsed conditions. The polarization direction of the VCSELs is consistently oriented along the [1210] a -direction. The degree of polarization increases from 0.13 below threshold to 0.72 above threshold. A process is demonstrated that utilizes bandgap-selective photoelectrochemical (PEC) undercut etching of an intracavity-embedded In 0.12 Ga 0.88 N sacrificial layer to achieve precise cavity length control and allow for top and bottom dielectric distributed Bragg reflector (DBR) mirrors.