Microstructured fiber cladding light stripper for kilowatt-class laser systems.

An all-glass microstructured high-power cladding mode stripper capable of handling cladding light of up to a power of approximately 350 W with stripping efficiencies >22 dB is presented. An optimized graded structure pattern increased the device's reliability and its power-handling capabilities. Subjected to a 500 h stress test, the device shows no degradation.

Single-mode monolithic fiber laser with 200 W output power at a wavelength of 1018 nm.

We report on an ytterbium-doped monolithic fiber laser at a wavelength of 1018 nm with an output power of 200 W in continuous wave operation. The optimal parameters for setting up such a high-power fiber laser with an ytterbium-doped fiber are investigated and discussed in detail. An in-house-developed pump light stripper and a single-mode fused fiber coupler were applied to use the fiber laser for core-pumping of ytterbium-doped high-power fiber amplifiers in a monolithic setup.