Ytterbium-doped large-mode-area silica fiber fabricated by using chelate precursor doping technique

We reported on a highly effective chelate precursor doping technique for Yb-doped large-mode-area (LMA) fiber manufacture. By accurately controlling the evaporation temperature and flow rate of carrier gas, the chelate precursor doping technique is capable of making Yb-doped LMA silica fiber with good uniformity free of center dip, low numerical aperture of similar to 0.056, large preform core size of 4.46 mm, and appropriate cladding absorption of 1.17 dB/m at 976.4 nm. Based on a single-end-pump all-fiber oscillator laser setup, the laser output at 1080 nm reached 700 W with slope efficiency of 54.2%. (C) 2014 Optical Society of Americ