title: Light funneling mechanism explained by magnetoelectric interference.
abstract: We investigate the mechanisms involved in the funneling of optical energy into subwavelength grooves etched on a metallic surface. The key phenomenon is unveiled thanks to the decomposition of the electromagnetic field into its propagative and evanescent parts. We unambiguously show that the funneling is not due to plasmonic waves flowing toward the grooves, but rather to the magnetoelectric interference of the incident wave with the evanescent field, this field being mainly due to the resonant wave escaping from the groove.
authors.affiliation: CNRS - Laboratoire de Photonique et de Nanostructures, Route de Nozay, 91460 Marcoussis, France. fabrice.pardo@lpn.cnrs.fr
authors.forename: Fabrice
authors.initials: F
authors.lastname: Pardo
authors.forename: Patrick
authors.initials: P
authors.lastname: Bouchon
authors.forename: Riad
authors.initials: R
authors.lastname: Haïdar
authors.forename: Jean-Luc
authors.initials: JL
authors.lastname: Pelouard