Selective excitations in surface enhance Raman scattering

Summary form only given. Surface enhanced Raman scattering (SERS) is a technique whereby the molecule under investigation is adsorbed on a metallic structure, typically made of silver. Raman signals are amplified through an interaction between the pump light and the surface plasmons propagating in the metal. Gratings are better suited to couple light into the surface plasmon modes owing to momentum conservation conditions. Opalline structures are made of a dosed pack, fcc arrangement of silica spheres with a precise control over the pitch and hence the gratings' depth. Coupling into surface plasmon modes of these two-dimensional structures should therefore, show a significant enhancement to specific vibrational lines.