Quasi-diffraction limited emission from an array of tapered laser diodes in volume Bragg grating external cavities

High-brightness single laser diodes based on the widespread taper design have demonstrated output powers of a few Watts with a single transverse mode operation. In this work we describe two external cavities intended to improve the spatial brightness of a bar of N=6 index-guided tapered laser diodes emitting around 975 nm. Our external cavity designs aim at controlling the slow-axis beam divergence of the whole array by inducing an angular-filtered feedback into the lasers. We take benefit of the angular selectivity of volume Bragg gratings to favour an asymmetrical feedback on one of these peaks.