Waveguide Raman Spectroscopy as a tool for the detection of nanometric metallic particles in glasses

Low-wavenumber inelastic Raman scattering (LOWIRS) was performed on dielectric films containing silver nanoparticlcs. Both the standard geometry and the waveguide configuration, which is the most suitable for planar guides, were used. LOWIRS results obtained for samples prepared using different methods such as co-deposition and ion exchange are compared, showing the advantages of waveguide Raman spectroscopy. The effect of the elastic medium and of the particle size on the Raman signal is considered and an evaluation of the mean size of the silver nanoparticles is reported.