The project PlasTips is devoted to the realization, characterization and optimization of plasmonic near field scanning probes. These plasmonic probes, based on metallic structures deposited on an elongated optical fiber, constitute a new promising development of the well know near field optical optical microscopy invented in the early 90's.
More precisely, nanostructured metallic systems are wellknown to support surface plasmon polariton modes (SPP) that couples an electromagnetic wave to a collective oscillation of the free electrons of the metal. Such surface modes are characterized by strong electromagnetic field localization and enhancement so that they appear as very promising for high integrated photonics and in particular for optical probes. Importantly, these modes have high effective refractive indices so that they generally cannot be directly excited by usual optical farfield methods.
However, by depositing a metallic nanostructure on a sharply elongated optical fiber, it is possible to couple the electromagnetic fiber guided mode to the metallic structure plasmon mode. We propose here to optimize the coupling efficiency between the fiber guided mode and the metallic structure plasmon mode by appropriate structuration of the metal surface.