title: Phase correlations and optical coherence.
abstract: We examine the properties of the recently introduced degrees of coherence regarding the phase correlations of the optical field. It is seen that some of these quantities are straightforwardly related to the limits of complete dependence and complete independence of phases, which were used as the extremes of complete coherence and complete incoherence by Zernike in 1938. Certain other coherence measures are not in agreement with these limits in all situations. Our results elucidate the physical meaning of coherence in electromagnetic fields.
authors.affiliation: Department of Physics and Mathematics, University of Eastern Finland, Joensuu, Finland. jani.tervo@uef.fi
authors.forename: Jani
authors.initials: J
authors.lastname: Tervo
authors.forename: Tero
authors.initials: T
authors.lastname: Setälä
authors.forename: Ari T
authors.initials: AT
authors.lastname: Friberg