Efficient unidirectional ridge excitation of surface plasmons.
Using leakage-radiation microscopy, we characterize the efficiency of unidirectional surface-plasmon excitation with periodic (800 nm) arrays of 130-nm-high and 330-nm-wide gold ridges on a thin gold film illuminated with a focused (5-microm-wide) laser beam. We demonstrate that, at the resonant wavelength of 816 nm, the excitation efficiency of > 0.4 can be obtained with >or= 5 ridges by adjusting the beam position. Conducting numerical simulations, we account for the experimental results and calculate the electric-field enhancement achieved near the gold surface.
Radko
I P
IP
Institute of Sensors, Signals and Electrotechnics, University of Southern Denmark, Odense M, Denmark. ilr@sense.sdu.dk
Bozhevolnyi
S I
SI
Brucoli
G
G
Martín-Moreno
L
L
García-Vidal
F J
FJ
Boltasseva
A
A
D017076:Computer-Aided Design; D004867:Equipment Design; D019544:Equipment Failure Analysis; D008027:Light; D012031:Refractometry / Q000295:instrumentation* / Q000379:methods*; D015203:Reproducibility of Results; D012542:Scattering, Radiation; D012680:Sensitivity and Specificity; D020349:Surface Plasmon Resonance / Q000295:instrumentation* / Q000379:methods*