Fabrication and research of high power and less-loss fiber combiner

A novel technique for end-pumped fiber combiner fabrication by multi-step process was reported. The mould, heat-shrinkable tube and filament were used to combine and fix the fibers. The combined input fiber beam can form a whole fiber without turning around before tapering, and was compatible with the commercial cut knife and welding machine. The fabricated 71-type fiber combiner had a endurable power of 1 400 W and the pump coupling loss was under 0.1 dB. The temperature distribution of the packaged fiber combiner was measured and analyzed. It shows that the polymer layer has a big temperature rise and limits the endurable power of the fiber combiner.