Fabrication of an InGaN multiple-quantum-well laser diode featuring high reflectivity semiconductor/air distributed Bragg reflectors

High-quality deeply-etched GaN-based semiconductor/air distributed Bragg reflectors (DBRs) have been fabricated. A 50% reduction relative to the value for reflectors of Fabry–Perot type in the threshold pump intensity was realized by the introduction of such DBRs at the ends of the laser cavity. The reflectivity of the grating was evaluated between 44% and 62%. Finite-difference time-domain simulation had earlier been used to obtain a design for the semiconductor/air DBRs, which provides high values for reflectivity despite a significant inclination from the vertical of the sidewalls of the structure.