In this work, we present measurements of efficiency-optimized 940 nm diode laser bars with long resonators that are constructed with robustly passivated output facets at the Ferdinand-Braun-Institut (FBH). The measurements were performed at room temperature on a test bench developed at HiLASE Centre, as a function of operating condition. The single-diode bars generated < 1.0 kW when tested with 1 ms pulses at 1-10Hz operating frequency, corresponding to < 1 J per pulse. The maximum electrical-to-optical efficiency was < 60 %, with operating efficiency at 1 kW of < 50%, limited by the ~ 200 μΩ resistance of the bar packaging. In addition, slow axis divergence at 1 kW was below 6° FWHM and spectral width at 1 kW was below 7 nm FWHM, as needed for pumping Yb-doped solid state amplifier crystals.

Date Published: 13 March 2015
PDF: 7 pages
Proc. SPIE 9348, High-Power Diode Laser Technology and Applications XIII, 934811 (13 March 2015); doi: 10.1117/12.2077558

Published in SPIE Proceedings Vol. 9348:
High-Power Diode Laser Technology and Applications XIII
Mark S. Zediker, Editor(s)