Surface enhanced Raman scattering (SERS) effect is currently exploited as the basis of a new type of optical labels for in vivo investigation of the tissues, especially for early medical diagnostic. Silver colloidal nanoparticles decorated with chemisorbed cresyl violet molecular species could act as hybrid SERS labels. Their Raman scattering properties have been characterized here using different SERS techniques, and probing different excitation

We report the formation of surface self-written waveguides by means of surface pyrolitons in lithium niobate. By a specific orientation of the crystal axis the quasi-local slow photorefractive response of lithium niobate was used to induce a self-confined beam exactly at the crystal-air interface. The mode profile of the photo-induced waveguide is strongly asymmetric due to the interface presence.