抄録
A UV-C laser diode is a promising light source for processing and machining applications due to photon
energy near 5 eV. Recently, our group reported a 272-nm laser diode (LD) fabricated on a high-quality
AlN substrate. Several key technologies are involved to achieve lasing; a low-dislocation-density AlN
substrate to reduce waveguide optical loss, and distributed polarization doping to increase the hole density
in the p-side AlGaN cladding of high Al composition. After introducing these key technologies, we
describe a highly productive on-wafer laser fabrication process in which a facet mirror is prepared by
dry- and wet-etching and coated with atomic layer deposited DBR (Distributed Bragg Reflector). These
technologies are expected to open up new UV-C applications and be widely implemented around the
world.
