Spectral beam combining of a single-mode 980-nm laser array for pumping of erbium-doped fiber amplifiers

Abstract

With a view to improve the power level and brightness of semiconductor pump lasers, we have resorted to a scalable implementation and achieved spectral beam combining through a low-quality-factor external cavity. For that purpose, a high-power single-mode laser array emitting up to 2.1 W at 3.2 A at 980 nm has been realized, which delivers 1.5 W in external cavity. A power of 0.66 W was finally coupled into the single-mode fiber, with a coupling efficiency of 44%. Pumping experiments of an erbium-doped fiber amplifier utilizing this laser have demonstrated efficiency and noise characteristics similar to what is usually obtained with conventional sources, with the noteworthy advantage of a lower gain excursion over the C-band.