Remote-excitation surface-enhanced Raman scattering with counter-propagating plasmons: silver nanowire-nanoparticle system

Abstract

Surface-enhanced Raman scattering (SERS) has emerged as a powerful tool to probe molecules at nanoscale. By utilizing plasmon polaritons on metallic nanowires, remote-excitation SERS can be achieved. Enhancement and modulation of remote-SERS intensity are vital for nano-optical spectroscopy. Counter-propagating plasmons have been excited in a plasmonic nanowire-nanoparticle (NW-NP) system and further utilized to perform remote-excitation SERS. By using the polarization of counter-propagating fields, remote-SERS intensity from NW-NP hot-spot junction was enhanced and modulated. Such capabilities of counter-propagating plasmons to control optical fields and SERS intensity at NW-NP junction can have implications in nanowire photonics and nano-optical spectroscopy.