Intensities and field enhancement of light scattered from periodic gratings: study OF Ag, Au and Cu surfaces

Abstract

In this paper we present scattering calculations and field enhancements e E for diffraction of light from Ag, Au and Cu grating surfaces. The results are obtained by using the extinction theorem that gives convergent results when the amplitude over the period of the grating is smaller than ∼ 0.3. It is shown that the field enhancement is much larger for Ag than for Au and Cu. The reason is that for light frequencies, the imaginary part of the dielectric constant for the first metal is smaller than that of the other two. We conclude that the main responsible for the surface enhanced Raman scattering is the classical electromagnetic enhancement that gives values of a factor of enhancement of 10 4−10 5.