title: High average power spectral beam combining of four fiber amplifiers to 8.2 kW.
abstract: We report on the incoherent beam combination of the four narrow-linewidth fiber amplifier chains running at different wavelengths. Each main amplifier stage consists of a large-mode-area photonic crystal fiber delivering more than 2 kW of optical power. The four output beams are spectrally combined to a single beam with an output power of 8.2 kW using a polarization-independent dielectric reflective diffraction grating mainly preserving the beam quality of the individual fiber amplifiers.
authors.affiliation: Fraunhofer Institute for Applied Optics and Precision Engineering, Albert-Einstein Str. 7, 07745 Jena, Germany.
authors.forename: Christian
authors.initials: C
authors.lastname: Wirth
authors.forename: Oliver
authors.initials: O
authors.lastname: Schmidt
authors.forename: Igor
authors.initials: I
authors.lastname: Tsybin
authors.forename: Thomas
authors.initials: T
authors.lastname: Schreiber
authors.forename: Ramona
authors.initials: R
authors.lastname: Eberhardt
authors.forename: Jens
authors.initials: J
authors.lastname: Limpert
authors.forename: Andreas
authors.initials: A
authors.lastname: Tünnermann
authors.forename: Klaus
authors.initials: K
authors.lastname: Ludewigt
authors.forename: Michael
authors.initials: M
authors.lastname: Gowin
authors.forename: Eric
authors.initials: E
authors.lastname: ten Have
authors.forename: Markus
authors.initials: M
authors.lastname: Jung