title: Optical angular momentum conversion in a nanoslit.
abstract: We demonstrate partial conversion of circularly polarized light into orbital angular momentum-carrying vortex light with opposite-handed circular polarization. This conversion is accomplished in a novel manner using the birefringent properties of a circular subwavelength slit in a thin metal film. Our technique can be applied over a very wide range of frequencies and even allows the creation of anisotropic vortices when using a slit without circular symmetry.
authors.affiliation: Leiden University, Huygens Laboratory, Leiden, Netherlands. chimento@physics.leidenuniv.nl
authors.forename: Philip F
authors.initials: PF
authors.lastname: Chimento
authors.forename: Paul F A
authors.initials: PF
authors.lastname: Alkemade
authors.forename: Gert W
authors.initials: GW
authors.lastname: 't Hooft
authors.forename: Eric R
authors.initials: ER
authors.lastname: Eliel