Enhanced transmission of light through a circularly structured aperture.
Using the differential theory of light diffraction by finite cylindrical objects, we study light transmission through a small circular aperture in a metallic screen with concentric corrugation around the nanohole. Poynting vector maps in the region below the screen show that the field enhancement compared with an unstructured aperture is obtained with corrugation lying on the entrance face of the screen. Corrugation on the exit face leads to a more directional radiation close to the normal to the screen. The spectral dependence of the transmission shows a sharp maximum linked with surface plasmon excitation.
Popov
Evgeny
E
Institut Fresnel, Unité Mixte de Recherche Associée au Centre National de la Recherche Scientifique 6133, Université de Provence, Faculté des Sciences et Techniques de St. Jérôme, 13397 Marseille 20, France. e.popov@fresnel.fr
Nevière
Michel
M
Fehrembach
Anne-Laure
AL
Bonod
Nicolas
N