title: Transverse mode coupling in an optical resonator.
abstract: Small-angle scattering due to mirror surface roughness is shown to couple the optical modes and deform the transmission spectra in a frequency-degenerate optical cavity. A simple model based on a random scattering matrix clearly visualizes the mixing and avoided crossings between multiple transverse modes. These effects are visible only in the frequency-domain spectra; cavity ringdown experiments are unaffected by changes in the spatial coherence, as they probe just the intracavity photon lifetime.
authors.affiliation: Huygens Laboratory, Leiden University, P.O. Box 9504, 2300 RA Leiden, The Netherlands. tklaassen@molphys.leidenuniv.nl
authors.forename: Thijs
authors.initials: T
authors.lastname: Klaassen
authors.forename: Johan
authors.initials: J
authors.lastname: de Jong
authors.forename: Martin
authors.initials: M
authors.lastname: van Exter
authors.forename: J P
authors.initials: JP
authors.lastname: Woerdman