SURFACE-ENHANCED RAMAN-SCATTERING ON SILVER GRATING - OPTIMIZED ANTENNALIKE GAIN OF THE STOKES SIGNAL OF 10(4)

Using a silver grating of variable groove depth overcoated by a thin film of copper phthalocyanine, we measured an increase of the Raman efficiency of 104 as compared to the flat case (copper phthalocyanine on a flat silver surface). This effect is due to the resonant excitation of delocalized surface plasmons. The value of 104 corresponds to an optimum groove depth of the grating which acts as a high gain directive antenna when surface plasmons resonance is achieved at the Stokes frequency.© 1995 American Institute of Physics.