title: Highly efficient Q-switched Yb:YAG channel waveguide laser with 5.6  W of average output power.
abstract: In this Letter, we present high-power continuous wave (CW) and Q-switched femtosecond laser-written Yb:YAG channel waveguide lasers. In Q-switched operation, obtained by a semiconductor saturable absorber mirror (SESAM), as well as in CW operation, the laser generates average output powers of more than 5.6 W and reaches slope efficiencies above 74%. The Q-switched laser operated at a maximum repetition rate of 5.4 MHz with a minimum pulse duration of 11 ns, and with a maximum pulse energy of 1 μJ. This laser has almost an order of magnitude higher average output power than previously reported Q-switched channel waveguide lasers.
authors.forename: Sargis
authors.initials: S
authors.lastname: Hakobyan
authors.forename: Valentin J
authors.initials: VJ
authors.lastname: Wittwer
authors.forename: Kore
authors.initials: K
authors.lastname: Hasse
authors.forename: Christian
authors.initials: C
authors.lastname: Kränkel
authors.forename: Thomas
authors.initials: T
authors.lastname: Südmeyer
authors.forename: Thomas
authors.initials: T
authors.lastname: Calmano