Laser-machined, kilowatt-class cladding light strippers with stripping efficiencies > 37 dB

Cladding light strippers are a crucial component for fiber-based laser and amplifier systems, stripping unabsorbed pump light behind the active fiber. Laser-machining presents an effective alternative to chemical etching in the production of high-power cladding light strippers. Here, we present improvements to laser-machined, microstructured cladding light strippers, which achieve cladding light attenuation up to 37.3 dB on a length of just 60 mm. We tested the high-power stripping capability of a cladding light stripper, achieving a stripped cladding light power of 1.2 kW. The result was limited by the available power. The cladding light strippers were designed by utilizing raytracing simulations to optimize the microstructure on the fiber towards homogenized stripping and increased cladding light attenuation. Afterwards, the most promising results were transferred to manufacturing and characterized. The availability of high-power, high attenuation microstructured cladding light strippers can help to improve future laser systems, possibly foregoing the need for chemical etching.