kW level fiber laser in all-fiber format

We report a high-power fiber laser in all-fiber format. The system consists of 36 pump ports, both counter and forward pump configuration are employed. In the experiment, 1 008 W fiber laser is obtained when 24 pump ports are employed with a total pump power of 1 477 W. The optical-to-optical conversion efficiency is 68%. The central wavelength of the output laser is 1 082 nm with a 3 dB bandwidth of 3 nm. Presently, the output power is limited by the pump source. It can be predicted that the laser power can be further scaled if more pump sources are employed.