2Â kW CW near single mode all-fiber Ytterbium-doped fiber laser

We demonstrated a CW all-fiber Ytterbium-doped fiber laser with master oscillator power amplifier configuration. The laser system generated 2.04 kW output power at 1080 nm with 78.5% total optical-to-optical efficiency. What is more, the output laser was near single mode with the beam quality factor M2 < 1.37 at the maximum power. It benefited from low splicing loss, proper heat management and effective controlling of fiber facet damage and the nonlinear effects through optimizing the whole system. The analysis showed that higher output power could be achieved with more pump power in this laser system.