title: Near-field scattered by a single nanoslit in a metal film.
abstract: Using a scanning near-field optical microscope, we visualize, in three dimensions, the electromagnetic field distribution near an isolated slit aperture in a thin gold film. At the metal-air interface and for a TM incident polarization, we confirm some recently observed results and show that the slit generates two kinds of surface waves: a slowly decaying surface plasmon polariton and a quasi-cylindrical wave that decreases more rapidly when moving away from the slit. These waves are not generated for a TE incident polarization. In a noncontact mode, we also observe how the transmitted light diverges in free space. At a small distance from the slit (< 2 microm), we find that the emerging light spreads in all directions for TM, forming an electromagnetic cloud, whereas it is concentrated above the slit for TE, forming a more directive light jet. The experimental images are in good agreement with the numerical simulations.
authors: Laboratoire Photons Et Matière, UPR CNRS A0005, Ecole Supérieure de Physique et de Chimie Industrielles (ESPCI), 10 rue Vauquelin, 75231 Paris Cedex 5, France. aigouy@optique.espci.fr
authors: Lionel
authors: L
authors: Aigouy
authors: Philippe
authors: P
authors: Lalanne
authors: Haitao
authors: H
authors: Liu
authors: Gwénaelle
authors: G
authors: Julié
authors: Véronique
authors: V
authors: Mathet
authors: Michel
authors: M
authors: Mortier