Linearly polarized narrow linewidth ytterbium-doped fiber laser at 1120 nm

Based on a spectrally symmetric cavity with respect to fiber Bragg grating bandwidth, using cladding pump technology, a 1120 nm continuous-wave narrow linewidth ytterbium-doped fiber laser is demonstrated. A maximum output power of 14.67 W is obtained corresponding to an optical efficiency of 63.5% to launched pump power. The measured center wavelength of the output laser is 1118.7 nm with a linewidth as narrow as 0.08 nm. The gain of the laser is more than 60 dB above the amplified spontaneous emission, and the polarization extinction ratio is 19.8 dB. As far as we are aware, this is the highest optical efficiency, largest amplified spontaneous emission suppression, and narrowest linewedth reported from cladding pumped linearly polarized 1120 nm fiber lasers. (C) 2017 Optical Society of America