m-Plane GaN-Based Blue Superluminescent Diodes Fabricated Using Selective Chemical Wet Etching

An m-plane-GaN based blue superluminescent diode was demonstrated utilizing the asymmetric chemical properties of the ±c facets. The non-reflecting -c plane facet, intended to prevent optical feedback along the c-axis waveguide, was fabricated by KOH wet etching. KOH selectively etched the cleaved -c facet leading to the formation of hexagonal pyramids without etching the +c facet. The peak wavelength and full width at half max were 439 and 9 nm at 315 mA, respectively, with an output power of 5 mW measured out of the +c facet.