Optical near field imaging of localized surface plasmons modes in metallic nanostructures integrated on dielectric waveguides

The study of surface plasmon-polaritons interactions in metallic nanostructures has been a topic of interest during last years due to their use in various areas such as the photonics, chemistry and biology. Example of use is found in biosensors for the efficient detection of biological analyte and in nanophotonic elements for on-chip photonics. Here, we study the interactions properties of localized surface plasmons in a hybrid waveguiding structure made of bi-dimensional array of gold nanowires vertically integrated on silicon-on-insulator waveguides across the near infrared spectrum. With the use of near-field scanning optical microscopy (NSOM) in perturbation mode, we qualitatively obtained the spectral response of such hybrid structure through intensity near field maps of the light propagation. These experimental results demonstrate that metallic nanostructures integrated on silicon are suitable for the development of localized surface plasmon integrated devices or metallic metamaterials.