Dispersion relation of surface plasmons on gold- and silver gratings

Abstract

The propagation velocity and damping of surface plasmons on sinusoidally modulated gold- and silver surfaces with different grating constants (ca. 4000 Å, 8000 Å and 15000 Å) are measured at wavelengths of 6471 Å and 5682 Å as function of the amplitude of the grating (up to ca. 300 Å). Earlier measurements of the changes of the dispersion relation produced by the sinusoidal profile could be improved by reducing the contribution of a second harmonic to the grating profile to less than about 0.06. Observed and calculated data, obtained with the Rayleigh method, show good agreement.