100 W ytterbium-doped monolithic fiber laser with fused angle-polished side-pumping configuration

Obtaining sufficient pump power is an engineering challenge in scaling fiber laser toward high power. A side-pumping all-fiber coupler with the coupling efficiency of 90.1% and the coupling power of 144.7 W was reported. The angle-polished pumping fiber was fused with the double-clad main fiber by carbon dioxide laser. The core of double-clad fiber was not interrupted. Based on this side-pumping coupler, a fiber laser with flexible configuration was demonstrated. The output power and the slope efficiency of fiber laser was 102.5 W and 77.1%, respectively. This side-pumping fiber coupler was beneficial to investigate efficient and reliable high power fiber lasers and amplifiers.