High-efficiency 970 nm multimode pumps

Ultra-reliable very efficient multimode diodes have been developed. 90 micrometer wide aperture chip-on-submount demonstrate 67% peak power conversion efficiency at 25 degrees C and 60% peak power efficiency at 85 degrees C heatsink temperature; while record high thermal limited peak power in excess of 15 W CW is achieved at 15 degrees C. State-of-the-art performance of Chip-on-Submount does not compromise its reliability; over 1,000,000 hours Mean Time Between Failures has been demonstrated. Cooler-less package design ensures thermal resistance of 4.5 degrees C/W from the Chip-on-Submount to external heatsink; coupling efficiency of 95% into 0.15 NA at over 5 W power in 100 mu m dia. fiber are routinely obtained. Results of multi-cell accelerated tests of packaged pumps yielded over 10 years of uninterrupted use MTBF at over 5W CW ex-fiber output.