title: Circular grating waveguide structures for intracavity generation of azimuthal polarization in a thin-disk laser.
abstract: We report on the generation of beams with azimuthal polarization using resonant grating waveguide structures (GWSs) inside an Yb:YAG thin-disk laser (TDL) oscillator. Two different GWS concepts were used to select the polarization of the emitted beam. The first uses the resonant reflection principle, and the second is based on the leaky-mode approach already reported in our previous work. Up to 93 W and 103 W of output power were extracted from a TDL with an optical efficiency, η(oo), of 36.2% and 40.1% using the first and the second approaches, respectively. In both cases, a pure azimuthal polarization and a beam quality factor, M2, of about 2.2 were measured. The design, fabrication, and different experimental results, as well as the laser performances for both GWSs, are discussed in the present Letter.
authors.affiliation: Institut für Strahlwerkzeuge (IFSW), Universität Stuttgart, Stuttgart, Germany. martin.rumpel@ifsw.uni‑stuttgart.de
authors.forename: Martin
authors.initials: M
authors.lastname: Rumpel
authors.forename: Matthias
authors.initials: M
authors.lastname: Haefner
authors.forename: Thomas
authors.initials: T
authors.lastname: Schoder
authors.forename: Christof
authors.initials: C
authors.lastname: Pruss
authors.forename: Andreas
authors.initials: A
authors.lastname: Voss
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Osten
authors.forename: Marwan Abdou
authors.initials: MA
authors.lastname: Ahmed
authors.forename: Thomas
authors.initials: T
authors.lastname: Graf