High power linearly polarized narrow linewidth ytterbium doped fiber laser at 1120 nm

Based on spectral symmetric cavity with respect to fiber Bragg gratings bandwidth, a 1120 nm 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 %. 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 60dB above the ASE, and the polarization extinction ratio is 19.8 dB. As far as we are aware, this is the highest optical efficiency, largest ASE suppression, and narrowest linewidth reported from cladding pumped linearly polarized 1120nm fiber lasers.