Frequency-narrowed external-cavity diode-laser-array bar

Abstract

We demonstrate that appropriately designed external cavities can be used to frequency narrow high-power diode-array bars. Using a commercial 20-W array, we narrow the linewidth to 50 GHz with 14 W of cw output power. A magnifying telescope and a cylindrical collimating lens minimize broadening owing to curvature in the alignment of the diode-array elements.