Fabrication of Pump Combiners for High Power Fiber Lasers

A custom fabrication procedure for pump combiners matched to a wide variety of double-clad fibers used in high power fiber lasers has been developed. Both combiners with and without feedthrough can be fabricated with an improved repeatability thanks to a specific mechanical setup that simplifies placing the fibers in their proper location within the input bundle before the tapering and fusion processes. Extensive characterization results on 7-to-1 and on (6+1)-to-1 combiners are confirming the validity of the proposed approach.