Experimental study on 1137 nm long wavelength Yb-doped fiber lasers

We reported the experiments of 1137 nm Yb-doped fiber laser, which was pumped by 976 nm laser diode and 1040 nm fiber laser respectively. Both of the output powers of the experiments were over hundred-milliwatt. The laser was a linear cavity. The reflectivities of the high reflectivity fiber Bragg grating and low reflectivity output coupler were 99.6% and 39.7% respectively. The gain media was an 8-meters-long Yb-doped fiber with a core diameter of 5 m. When the power of the 976 nm laser diode was 912 mW, the output power of 1137 nm laser reached to 182 mW corresponding to the slope efficiency of 28.5%. When pumped by 1.59 W 1040 nm fiber laser, a 278 mW 1137 nm laser power was obtained with a slope efficiency of 25%. We also compared the differences of these two pumping methods.