Strongly polarized scattering in surface enhanced Raman spectroscopy of randomly distributed molecules on gold nanowires

Abstract

We study the polarized Surface Enhanced Raman Scattering from randomly oriented molecules adsorbed on near-field coupled gold nanowires. We show that the scattering is polarized always along the wire-to-wire nanocavities. We find the exact angular dependence for the polarized, unpolarized, parallel- and cross-polarized SERS intensity. Finally we develop a model that fits the experimental data and allows to measure the field enhancement and the re-radiation enhancement factors, independently, and retrieve the depolarization ratio of the probe molecules.