High power ytterbium-doped double clad fiber laser with dual-end pumping scheme

The energy level structure, the spectrum characteristic and the laser emission characteristic of ytterbium ions were analyzed. A high power cladding-pumped ytterbium-doped fiber laser generating 61.6 W continuous-wave output power at 1.1 μm with 55% slope efficiency was demonstrated. Two diode-laser-stacks (wavelength 915 nm) were used for pumping from the two ends of the fiber. A dichroic mirror with 45° high reflectivity at (1 100±10) nm and high transmissivity at (910±10) nm was used for exporting laser. The cooperative luminescence effect in the ytterbium doped double clad fiber was obtained in the experiment, and the mechanism of this effect was analyzed as the absorption and emission of Yb3+ ion’ pairs.