Electrodynamic calculations of the surface-enhanced electric intensities on large Ag spheroids

Electrodynamic calculations of the electric field on the surface of Ag prolate spheroids indicate that, as the size increases, the field enhancement decreases rapidly and the resonance shifts to longer wavelengths, the resonance linewidth broadens, and a new set of higher-order resonances appears. The calculated surface-averaged intensity and its wavelength dependence for 200×100 n${\mathrm{m}}^2$ prolate spheroids in air, water, and cyclohexane can be compared to surface-enhanced Raman scattering results from lithographically produced Ag spheroids.