Metallized tip amplification of near-field Raman scattering

We have observed the amplification of near-field Raman scattering by using an apertureless near-field scanning optical microscope the tip of which is a 40 nm silver-layer-coated cantilever of an atomic force microscope. Local ized surface plasmon polaritons are excited at the metallized tip apex of t he cantilever thereby producing a field enhancement effect. We have unambig uously observed the amplification of the near-field signal due to the field enhancement by measuring the Raman spectra of Rhodamine 6G molecules adsor bed on 10 nm silver islands film when the metallized tip approached the sur face of the sample. In addition, due to the nature of near-field optics, sp ectral mapping of Raman Scattering was attained with a 50 nm super-resolvin g power. (C) 2000 Published by Elsevier Science B.V.