Integrated Kilowatt Level Fiber Laser Based on Side Pumping

We report here a kW-level integrated all-fiber laser oscillator with fiber Bragg gratings (FGBs) and side-pumping coupler fabricated directly on the ytterbium-doped fiber (YDF). Through side pumping technology, the output power of the oscillator reaches to 1052 W when pumping with two 976 nm laser diodes (LD), corresponding to the optical-optical conversion efficiency of about 71 %. This new type of fiber laser is beneficial for reducing the splicing point, and has development potential in improving efficiency and increasing system stability.