title: Plasmonic tomography of optical vortices.
abstract: We present a method for analyzing the wavefront of optical vortices that does not involve interferometry but rather uses surface plasmon polaritons (SPPs). We employ a subwavelength slit in a gold film to cut slices from an optical vortex beam and measure the diffraction of the generated SPPs by scattering them off a second slit. By moving the slits across the vortex beam, we create a tomogram, from which we can determine the vortex charge of the incident beam at a glance. We present results for vortex beams of integer- and half-integer-vortex charge.
authors.affiliation: Huygens Laboratory, Leiden University, P.O. Box 9504, 2300 RA Leiden, The Netherlands. chimento@molphys.leidenuniv.nl
authors.forename: Philip F
authors.initials: PF
authors.lastname: Chimento
authors.forename: Gert W
authors.initials: GW
authors.lastname: 't Hooft
authors.forename: Eric R
authors.initials: ER
authors.lastname: Eliel