Pump-signal combiner with large-core signal fiber feed-through for fiber lasers and amplifiers.
A pump-signal combiner with a new processing method is reported in this paper. The core deformation of the signal fiber can be avoided by this method, and an 8+1 to 1 pump-signal combiner with 100 μm core-signal fiber feed-through is fabricated. The pump and signal coupling efficiencies are 96.8% and 98.0%, respectively. Furthermore, this pump-signal combiner is applied to a CW large mode area fiber laser with a counter pump configuration. The output power of the laser is 87 W.