Near-field scanning optical microscope using a metallized cantilever tip for nanospectroscopy

Abstract
We have developed a NSOM which has a metallic probe tip and a highly focused evanescent light field spot. Evanescent illumination effectively rejects the background light, e.g. the stray light from the shaft of the probe. By suppressing the stray light and utilizing the field enhancement generated by the metallic probe, a sudden increment of the fluorescence was observed in the near-field region. We have used this for near-field Raman scattering detection of molecules vibrations with the aid of surface enhanced Raman scattering. One specific stokes-Raman-shifted lines was observed by near-field excitation together with several other lines that were excited by the far-field light.