Ytterbium fiber laser emitting at 1160 nm

We have realized ytterbium fiber laser emitting at 1160 nm. To avoid a competition with a spontaneous lasing at shorter wavelengths we pumped laser into the core at wavelength of 1070 nm. Cladding pumped Yb-laser was used as a pump source. Also, the active fiber was heated up to 70°C to increase the absorption of the pump power and suppress the spontaneous emission. The lasing efficiency slope of 45% was measured. A maximum output power of 3.2 W was achieved.