We studied the influence of localized surface plasmon resonance (LSPR) sustained by arrays of metallic nanoparticles on the efficiency of surface-enhanced Raman scattering (SERS). We found that the Raman enhancement that originates from the excitation of LSPR does depend on the particle shape. Two different shapes were investigated: cylindrical particles, for which the maximum of Raman enhancement occurred for a LSPR located around 650 nm, and ellipsoidal particles, which exhibit the strongest SERS signal at 700 nm. These results are compared to an analytical model in the quasistatic approximation. This model, though being quite simple, can give an explanation of the observed differences in terms of the lightning rod effect.

The role of surface plasmon in second harmonic generation from arrays of gold nanorod particles excited by femtosecond laser pulses is investigated as a function of incident light polarization and irradiation wavelength. In addition to photoluminescence, a peak of second harmonic is observed and is found to depend on the polarization and wavelength of the fundamental frequency laser beam. In particular, the authors found similarities between extinction spectra of the nanoparticles and spectra of emmitted second harmonic. This behavior can be explained by resonant excitation of localized surface plasmon resonances.