Non–diffraction-limited light transport by gold nanowires
Institute for Experimental Physics and Erwin Schrödinger
Institute for Nanoscale Research, Karl-Franzens-University Graz
A-8010 Graz, Austria
Accepted: 23 September 2002
We show that metal nanowires sustaining collective electron oscillations (surface plasmon polaritons) can be used as optical waveguides. Thereby, the use of a metal allows to overcome the limitations of miniaturization imposed on conventional dielectric waveguides due to diffraction. To demonstrate this effect we investigate a 200 wide and 50 high gold nanowire locally excited at a light wavelength of 800. By direct imaging the optical near-field with subwavelength-resolution photon scanning tunneling microscopy we observe light transport along the nanowire over a distance of a few μm. Besides the realization of unprecedented integration densities of photonic devices, metal nanowires could be effectively used to optically address individual nanostructures or molecules.
PACS: 42.79.Gn – Optical waveguides and couplers / 42.25.Bs – Wave propagation, transmission and absorption / 71.45.Gm – Exchange, correlation, dielectric and magnetic response functions, plasmons
© EDP Sciences, 2002