a A 15 kW Fiber-Coupled Diode Laser for Pumping Applications

New solid-state laser architectures require higher pump powers. In this paper we report the development of a new fiber-coupled diode laser capable of generating 15 kW from a 2 mm diameter fiber with a 0.22 NA, representing a brightness of 220 mm.mrad at a single wavelength. In this design a special beam transformation technique has been developed to achieve these specifications at a single wavelength without the wavelength combination technique employed in high power diode lasers used in material processing applications. The specific laser presented here is at 938 nm with a spectral bandwidth of 3.1 nm FWHM, but the same architecture is possible for wavelengths between 910 and 1060 nm.