LAUSR

Abstract A study of Raman scattering enhancement by single hemispheroidal silver nanoislands grown on a glass surface via out-diffusion technique combined with thermal poling of the glass is presented. It was demonstrated in the experiments and confirmed by numerical modeling that maximal enhancement of Raman signal occurs when the diameter of a silver nanoisland fell between 90 and 115 nm, and the thickness of the Rhodamine 6G dye analyte layer was ∼3 nm. In this case the surface plasmon resonance (SPR) in the silver hemispheroid corresponded to the wavelength of the laser used to excite Raman scattering, 532 nm, and maximal enhancement by an single hemispheroidal nanoisland, ∼5 × 10 7 , was close to one provided by a typical silver nanoisland film. Varying lateral diameter of the silver hemispheroid allowed us shifting the SPR wavelength and enhancing particular lines in R6G Raman spectra.