830 nm InGaAs quantum well lasers with very low beam divergence

Abstract

We report on our design and fabrication of 830 nm high power semiconductor lasers with extremely low beam divergence. Here we propose a novel approach in which by combining asymmetric waveguide and a feature called “pins” together, we were able to design an optimized epi structure which not only produces a beam divergence of less than 16°, but also has very good growth tolerance as well. Tested devices show the beam divergence is as small as 13°, yet they still retain very high slope efficiency of around 1.15 W/A and low threshold current of 400 mA for the devices with cavity length being 2 mm long, and ridge width being 40 μm wide.