Local detection of electromagnetic energy transport below the diffraction limit in metal nanoparticle plasmon waveguides.
Achieving control of light-material interactions for photonic device applications at nanoscale dimensions will require structures that guide electromagnetic energy with a lateral mode confinement below the diffraction limit of light. This cannot be achieved by using conventional waveguides or photonic crystals. It has been suggested that electromagnetic energy can be guided below the diffraction limit along chains of closely spaced metal nanoparticles that convert the optical mode into non-radiating surface plasmons. A variety of methods such as electron beam lithography and self-assembly have been used to construct metal nanoparticle plasmon waveguides. However, all investigations of the optical properties of these waveguides have so far been confined to collective excitations, and direct experimental evidence for energy transport along plasmon waveguides has proved elusive. Here we present observations of electromagnetic energy transport from a localized subwavelength source to a localized detector over distances of about 0.5 microm in plasmon waveguides consisting of closely spaced silver rods. The waveguides are excited by the tip of a near-field scanning optical microscope, and energy transport is probed by using fluorescent nanospheres.
Maier
Stefan A
SA
Thomas J. Watson Laboratory of Applied Physics, California Institute of Technology, Mail Stop 128-95, Pasadena, California 91125, USA. stmaier@caltech.edu
Kik
Pieter G
PG
Atwater
Harry A
HA
Meltzer
Sheffer
S
Harel
Elad
E
Koel
Bruce E
BE
Requicha
Ari A G
AA
D055590:Electromagnetic Phenomena / Q000295:instrumentation* / Q000379:methods; D004735:Energy Transfer; D004867:Equipment Design; D008422:Materials Testing / Q000295:instrumentation* / Q000379:methods; D008855:Microscopy, Electron, Scanning / Q000379:methods; D008856:Microscopy, Fluorescence / Q000379:methods*; D036103:Nanotechnology / Q000295:instrumentation* / Q000379:methods; D011827:Radiation; D012834:Silver / Q000737:chemistry*; D020349:Surface Plasmon Resonance / Q000295:instrumentation / Q000379:methods*; D014159:Transducers
D012834:Silver