Measurement And Analysis Of Internal Loss And Injection Efficiency For Continuous-Wave Blue Semipolar (20(2)Over-Bar(1)Over-Bar Iii-Nitride Laser Diodes With Chemically Assisted Ion Beam Etched Facets

Continuous-wave blue semipolar (20 (2) over bar(1) over bar) III-nitride laser diodes were fabricated with highly vertical, smooth, and uniform mirror facets produced by chemically assisted ion beam etching. Uniform mirror facets are a requirement for accurate experimental determination of internal laser parameters, including internal loss and injection efficiency, which were determined to be 9 cm(-1) and 73%, respectively, using the cavity length dependent method. The cavity length of the uncoated devices was varied from 900 mu m to 1800 mu m, with threshold current densities ranging from 3 kA/cm(2) to 9 kA/cm(2) and threshold voltages ranging from 5.5V to 7 V. The experimentally determined internal loss was found to be in good agreement with a calculated value of 9.5 cm(-1) using a 1D mode solver. The loss in each layer was calculated and in light of the analysis several modifications to the laser design are proposed. (C) 2016 AIP Publishing LLC.