All-fiber kilowatt signal combiners for high power fiber lasers

Continuous wave fiber lasers have become the key tool for material laser processing applications like cutting, welding, and soldering, and their power scaling to several kilowatts to allow the fast machining of thicker and thicker materials is an already well-established path. As the demand for higher output power increases, however, the onset of nonlinear effects and fiber damages must be taken into account. Beam combining techniques can help overcoming these limitations since they allow the power scaling to the kilowatt range by merging the output of several hundred watt fiber lasers into a single large core delivery fiber [1,2].