High-power single mode (>1W) continuous wave operation of longitudinal photonic band crystal lasers with a narrow vertical beam divergence

Abstract

We report on 980nm InGaAs∕AlGaAs lasers with a broad waveguide based on a longitudinal photonic band crystal concept. The beam divergence measured as full width at half maximum was as narrow as <5° (vertical). Broad area 100μm multimode devices demonstrated >15W pulsed operation as limited by the current source. Significantly increased modal spot size enabled stable single lateral mode operation in broad ridge 10μm stripes. Maximum continuous wave power in single mode regime of 1.3W for 10μm wide stripe lasers was obtained, being limited by the catastrophic degradation of the unpassivated laser facets.