Plasmonics: Metallic Nanostructures and Their Optical Properties VII
DOI: 10.1117/12.829965
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Here we report the design, the fabrication and measurement of a photonic-plasmonic device that is fully compatible with AFM microscopy and surface enhanced Raman spectroscopy. The physical mechanism exploited is the adiabatic compression of Surface Plasmon Polaritons which propagate along a silver nanocone generating a very high electric field at the tip end. A photonic crystal cavity is employed to efficiently couple the external laser radiation with the nanocone. The reported measurements demonstrate the accumulation of the electric field at the tip of the nanocone that allow the detection of a few molecules located near the tip end. The estimated Raman enhancement factor is about 106 with respect to a standard configuration. The present results open a good perspective for the development of an integrated Raman-AFM microscopy able to perform both topography and chemical mapping in label free condition with a spatial resolution comparable to the tip end.