Paper: 2005 Plasmonic light scattering from nanoscopic metal tips

Plasmonic light scattering from nanoscopic metal tips

Reviews and Highlights Quantum Science Molecular and Soft-matter Ultrafast Nano-optics and Nanophotonics Mineralogy and Geochemistry

C. C. Neacsu, G. Steudle, and M. B. Raschke
Appl. Phys. B 71, 201402 (2005)

Linear light scattering by individual nanoscopic metal wire tips is investigated. Using evanescent-wave excitation, the spectral and polarization dependence of the emission are addressed. Choosing gold and tungsten as representative tip materials, intense scattering and a strongly plasmonresonant behavior observed for gold contrasts a comparatively weak and spectrally flat response for tungsten. Spectral dependence and local-field enhancement are found to be sensitive to details of the structural parameters and can be described by a simple model. The results provide selection criteria for tips to be used in scattering-type near-field microscopy or for photoemission in inelastic tunneling spectroscopy.