Highly-efficient high-power pumps for QCW fiber lasers

Abstract

We report on new generation high power multimode pumps based on long cavity AlGaInAs/GaAs 9XX-nm chips. These chips are produced in high volume by Solid Source MBE growth on four-inch diameter GaAs wafers. Uniformity of material grown on multi-four-inch wafers is presented. We also demonstrate the uniformity of lasing parameters of ChipOn-Submount (COS) across individual four-inch wafers and across the entire 19”-diameter MBE-platen growth area. We discuss the performance of high power pumps based on simple spatial beam combining. Ultimate ex-fiber (~100 µm core diameter) power launched in CW and QCW modes of operation was recorded in excess of 350 W and 450W, correspondingly. We demonstrate fully wavelength stabilized operation in driving current range in excess of 22A and exfiber power in excess of 135W.