Tapered waveguide high power AlGaInN laser diodes and amplifiers for optical integration and quantum technologies

Abstract

The AlGaInN material system allows for laser diodes to be fabricated over a very wide range of wavelengths from UV, ~380 nm, to the visible ~530 nm, by tuning the indium content of the laser GaInN quantum well. This makes nitride laser diodes suitable for a vast range of applications, but most of them require not only the proper wavelength emission, but also high optical power and good beam quality. The typical approach - wide ridge waveguide - often suffers from spatial multimode emission (low beam quality). We report our initial results with tapered GaN lasers to increase the maximum optical power of the device with a good beam profile. This combination opens new possibilities for GaN laser diode technology in quantum technologies including optical atomic clocks and quantum gravity sensors.