Continuous-wave blue semipolar (20 2 ¯ 1 ¯) 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 μm to 1800 μm, with threshold current densities ranging from 3 kA/cm2 to 9 kA/cm2 and threshold voltages ranging from 5.5 V 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.
Becerra, D. L., Kuritzky, L. Y., Nedy, J., Saud Abbas, A., Pourhashemi, A., Farrell, R. M., … Nakamura, S. (2016). Measurement and analysis of internal loss and injection efficiency for continuous-wave blue semipolar (202¯1¯) III-nitride laser diodes with chemically assisted ion beam etched facets. Applied Physics Letters, 108(9), 091106. doi:10.1063/1.4943143
This work was supported in part by the KACST-KAUST-UCSB Solid State Lighting Program and by the Solid State Lighting and Energy Electronics Center (SSLEEC) at UCSB. A portion of this work was done in the UCSB nanofabrication facility, part of the National Science Foundation funded NNIN. This work made use of MRL Central Facilities supported by the MRSEC Program of the National Science Foundation under Award No. DMR05-20415.