Highly n-doped GaN is a material of a reduced refractive index which may substitute AlGaN as a cladding layer in InGaN laser diodes. In this study we focus on the determination of the optical absorption and the refractive index of GaN:O having the electron concentration between 1·10¹⁸ - 8·10¹⁹ cm^-3. Though the measured absorption coefficient for the highest doped GaN are rather high (200 cm^-1) we show, using an optical mode simulation, that you can design a InGaN laser diode operating in blue/green region with decent properties and low optical losses. We propose to use relatively thin AlGaN interlayer to separate plasmonic GaN from the waveguide and thus to dramatically reduce the optical losses.

Date Published: 27 February 2012
PDF: 8 pages
Proc. SPIE 8262, Gallium Nitride Materials and Devices VII, 826216 (27 February 2012); doi: 10.1117/12.906866

Published in SPIE Proceedings Vol. 8262:
Gallium Nitride Materials and Devices VII
Jen-Inn Chyi; Yasushi Nanishi; Hadis Morkoç; Joachim Piprek; Euijoon Yoon, Editor(s)