A kW Continuous-Wave Ytterbium-Doped All-Fiber Laser Oscillator with Domestic Fiber Components and Gain Fiber**Supported by the National High-Technology Research and Development Program of China under Grant No 2013AA031501, and the Fundamental Research Funds for the Central Universities under Grant No 2014TS017.

Abstract

We demonstrate a kW continuous-wave ytterbium-doped all-fiber laser oscillator with all domestic fiber components: a 7 × 1 fused fiber bundle combiner, a fiber Bragg grating and a double-clad gain fiber. The oscillator operates at 1079.48 nm with 80.94% slope efficiency and shows no limit of temperature and nonlinear effects. These indicate that the passive fiber components and the gain fiber are all qualified for the high power environment. No evidence of the signal power roll-over shows that this oscillator possesses the capacity to higher output with available pump power.