Highly-integrated signal and pump combiner in chirally-coupled-core fibers

Integrated fiber components enable compact and robust laser systems but are usually not available with specialty fibers. However, specialty fibers allow power scaling of fiber lasers and amplifiers with all advantages of these fiber designs. In this context, chirally-coupled-core fibers show promising properties for optical fiber components. In this paper, we present the development of a highly-integrated signal and pump combiner in chirally-core-fibers using a side-pumping technology. Combining up to four fiber-coupled pump diodes, a pump-light limited power handling of 600 W can be achieved with an efficiency of 78%. The combiner was tested in a side-pumped single-frequency all-fiber amplifier but can also be implemented in almost any fiber laser or amplifier.