title: Er-doped photonic crystal fiber amplifier with 70 W of output power.
abstract: We report for the first time, to the best of our knowledge, on a large mode area Er-doped photonic crystal fiber laser system. The fiber core had a diameter of 40 μm and NA of <0.04 leading to a mode field diameter of about 31 μm around 1550 nm wavelength. More than 70 W of single-frequency output power at 1556 nm could be extracted using a master-oscillator power-amplifier scheme. Near diffraction limited output beam quality has been verified by measuring the TEM(00) content with a nonconfocal scanning ring cavity.
authors.affiliation: Laser Zentrum Hannover e.V., Hollerithallee 8, D-30419 Hannover, Germany. v.kuhn@lzh.de
authors.forename: Vincent
authors.initials: V
authors.lastname: Kuhn
authors.forename: Dietmar
authors.initials: D
authors.lastname: Kracht
authors.forename: Jörg
authors.initials: J
authors.lastname: Neumann
authors.forename: Peter
authors.initials: P
authors.lastname: Wessels