title: The influence of whispering gallery modes on the far field of ring lasers.
abstract: We introduce ring lasers with continuous π-phase shifts in the second order distributed feedback grating. This configuration facilitates insights into the nature of the modal outcoupling in an optical cavity. The grating exploits the asymmetry of whispering gallery modes and induces a rotation of the far field pattern. We find that this rotation can be connected to the location of the mode relative to the grating. Furthermore, the direction of rotation depends on the radial order of the whispering gallery mode. This enables a distinct identification and characterization of the mode by simple analysis of the emission beam.
authors.affiliation: Institute of Solid State Electronics, TU Wien, Floragasse 7, 1040 Vienna, Austria.
authors.forename: Rolf
authors.initials: R
authors.lastname: Szedlak
authors.affiliation: Center for Micro- and Nanostructures, TU Wien, Floragasse 7, 1040 Vienna, Austria.
authors.forename: Martin
authors.initials: M
authors.lastname: Holzbauer
authors.affiliation: Institute of Solid State Electronics, TU Wien, Floragasse 7, 1040 Vienna, Austria.
authors.forename: Donald
authors.initials: D
authors.lastname: MacFarland
authors.affiliation: Center for Micro- and Nanostructures, TU Wien, Floragasse 7, 1040 Vienna, Austria.
authors.forename: Tobias
authors.initials: T
authors.lastname: Zederbauer
authors.affiliation: Center for Micro- and Nanostructures, TU Wien, Floragasse 7, 1040 Vienna, Austria.
authors.forename: Hermann
authors.initials: H
authors.lastname: Detz
authors.affiliation: Institute of Solid State Electronics, TU Wien, Floragasse 7, 1040 Vienna, Austria.
authors.forename: Aaron Maxwell
authors.initials: AM
authors.lastname: Andrews
authors.affiliation: Institute of Solid State Electronics, TU Wien, Floragasse 7, 1040 Vienna, Austria.
authors.forename: Clemens
authors.initials: C
authors.lastname: Schwarzer
authors.affiliation: Center for Micro- and Nanostructures, TU Wien, Floragasse 7, 1040 Vienna, Austria.
authors.forename: Werner
authors.initials: W
authors.lastname: Schrenk
authors.affiliation: Institute of Solid State Electronics, TU Wien, Floragasse 7, 1040 Vienna, Austria.|Center for Micro- and Nanostructures, TU Wien, Floragasse 7, 1040 Vienna, Austria.
authors.forename: Gottfried
authors.initials: G
authors.lastname: Strasser