Near 1 kW of continuous-wave power from a single high-efficiency diode-laser bar

Near 1 kW of continuous-wave output power has been obtained from a single I-cm-wide diode-laser bar. Mounted on a water-cooled microchannel heat sink, the operating wavelength was near 940 nm (at similar to 400 W) and the measured thermal resistance was as low as 0.08 degrees C/W. Maximum power conversion efficiencies (PCEs) of 70% and 67% were obtained from high-fill-factor bars with cavity lengths of 4 and 5 mm, respectively. A maximum PCE of 72.2% was achieved with 3-mm broad-area single emitters. On-going lifetime data may signal the stable operation at unprecedented powers.