Ultraviolet GaN-Based Superluminescent Diodes with Inclined Facets

In this work, we demonstrated the first ultraviolet (UV) superluminescent diodes (SLDs) with AlGaN/GaN-based multiple quantum wells (MQWs), emitting at 360 nm. The UV SLD samples were grown on the c-plane sapphire substrates using molecular beam epitaxy (MBE) and were processed into ridge waveguides with inclined facets. The epitaxial structure exhibits excellent crystalline quality with low dislocation density. Optical mode simulations reveal strong confinement within the QWs, with a confinement factor of 3.2%. Moreover, the fabricated UV SLDs achieve a maximum optical power of 8 mW and an external quantum efficiency (EQE) of 7.6% at a current density of 3.5 kA/cm2. These results represent a significant advancement in III-nitride light-emitting devices, paving the way for UV superluminescent light sources for applications such as UV optical communications, photolithography, and medical imaging.