Highly doped GaN: a material for plasmonic claddings for blue/green InGaN laser diodes

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.