Subwavelength focusing and guiding of surface plasmons.
The constructive interference of surface plasmon polaritons (SPP) launched by nanometric holes allows us to focus SPP into a spot of high near-field intensity having subwavelength width. Near-field scanning optical microscopy is used to map the local SPP intensity. The resulting SPP patterns and their polarization dependence are accurately described in model calculations based on a dipolar model for the SPP emission at each hole. Furthermore, we show that the high SPP intensity in the focal spot can be launched and propagated on a Ag strip guide with a 250 x 50 nm2 cross section, thus overcoming the diffraction limit of conventional optics. The combination of focusing arrays and nano-waveguides may serve as a basic element in planar nano-photonic circuits.
Yin
Leilei
L
Materials Science Division, Argonne National Laboratory, Argonne, Illinois 60439, USA.
Vlasko-Vlasov
Vitali K
VK
Pearson
John
J
Hiller
Jon M
JM
Hua
Jiong
J
Welp
Ulrich
U
Brown
Dennis E
DE
Kimball
Clyde W
CW
D004867:Equipment Design; D019544:Equipment Failure Analysis; D049329:Nanostructures / Q000032:analysis / Q000737:chemistry*; D036103:Nanotechnology / Q000295:instrumentation* / Q000379:methods; D055095:Optics and Photonics / Q000295:instrumentation*; D012031:Refractometry / Q000295:instrumentation* / Q000379:methods; D020349:Surface Plasmon Resonance / Q000295:instrumentation* / Q000379:methods