Extraordinary transmission through a single coaxial aperture in a thin metal film.
We investigate experimentally the transmission properties of single sub-wavelength coaxial apertures in thin metal films (t = 110 nm). Enhanced transmission through a single sub-wavelength coaxial aperture illuminated with a strongly focused radially polarized light beam is reported. In our experiments we achieved up to four times enhanced transmission through a single coaxial aperture as compared to a (hollow) circular aperture with the same outer diameter.We attribute this enhancement of transmission to the excitation of a TEM-mode for illumination with radially polarized light inside the single coaxial aperture. A strong polarization contrast is observed between the transmission for radially and azimuthally polarized illumination. Furthermore, the observed transmission through a single coaxial aperture can be strongly reduced if surface plasmons are excited. The experimental results are in good agreement with finite difference time domain (FDTD) simulations.
Banzer
Peter
P
Max Planck Institute for the Science of Light, Guenther-Scharowsky-Str. 1, D-91058 Erlangen, Germany. peter.banzer@mpl.mpg.de
Kindler
Jochen
J
Quabis
Susanne
S
Peschel
Ulf
U
Leuchs
Gerd
G
D003198:Computer Simulation; D008027:Light; D008567:Membranes, Artificial; D008670:Metals / Q000737:chemistry*; D008956:Models, Chemical; D012031:Refractometry / Q000379:methods*; D012542:Scattering, Radiation
D008567:Membranes, Artificial; D008670:Metals