Observation of enhanced transmission for s-polarized light through a subwavelength slit.
Enhanced optical transmission (EOT) through a single aperture is usually achieved by exciting surface plasmon polaritons with periodic grooves. Surface plasmon polaritons are only excited by p-polarized incident light, i.e. with the electric field perpendicular to the direction of the grooves. The present study experimentally investigates EOT for s-polarized light. A subwavelength slit surrounded on each side by periodic grooves has been fabricated in a gold film and covered by a thin dielectric layer. The excitation of s-polarized dielectric waveguide modes inside the dielectric film strongly increases the s-polarized transmission. A 25 fold increase is measured as compared to the case without the dielectric film. Transmission measurements are compared with a coupled mode method and show good qualitative agreement. Adding a waveguide can improve light transmission through subwavelength apertures, as both s and p-polarization can be efficiently transmitted.
Guillaumée
M
M
Swiss Centre for Electronics and Microtechnology, CSEM SA, Jaquet-Droz 1, CH-2002 Neuchâtel, Switzerland. mickael.guillaumee@csem.ch
Nikitin
A Yu
AY
Klein
M J K
MJ
Dunbar
L A
LA
Spassov
V
V
Eckert
R
R
Martín-Moreno
L
L
García-Vidal
F J
FJ
Stanley
R P
RP