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DS: Fachverband Dünne Schichten
DS 15: Plasmonics and Nanophotonics O-I (jointly with HL and O)
DS 15.1: Talk
Monday, March 14, 2011, 15:00–15:15, PHY C213
Quasistatic plasmon resonances in the visible spectral range of arbitrary shaped nano-grooves — •Camille Maxime1,2, Aude Barbara1,2, and Pascal Quemerais1,3 — 1Institut Néel, CNRS-UJF, Grenoble, France — 2IAPP, TU Dresden, Germany — 3MPI-PKS, Dresden, Germany
As we previously reported, plasmonic resonances inside rectangular nano-grooves periodically made on a silver surface present a cross-over between two physical regimes [1]: an optical one for groove widths w larger than 10 nm, and a quasistatic one for lower values. In that case, the grooves resonate in the visible range even for grooves height h of only a few nanometers (5-15 nm). A very strong light absorption occurs at the resonance together with an electric field intensity enhancement (EFIE) of about 400. These results were obtained with a method only available for rectangular shapes. To generalize, we have implemented a surface integral method [2] and adapted it to periodic profiles to avoid surface boundaries problems. As an example, the behaviour of Gaussian shaped grooves was studied. It fully confirms the transition to a quasistatic regime as the groove width decreases leading to unusual EFIE (up to about 10000) and a very strong light absorption. These original results are fundamental to explain surface enhanced Raman scattering (SERS) experiments such as the historical ones of Albano et al.[3].
[1] J. Le Perchec et al., Phys. Rev. Lett. 100, 066408 (2008)
[2] A.A. Maradudin et al., Ann. Phys. 203, 255 (1990)
[3] E.V. Albano et al., Phys. Rev. Lett. 51, 2314 (1983)