Abstract

The strong coupling between photons and surface plasmons that occur on rough metal surfaces permits optical measurements of the shift of the surface plasma resonance frequency when the metal surface is covered with a thin film. Thin, discontinuous silver sulfide tarnish films on silver shift the resonance to lower frequencies and also damp the resonance, in agreement with surface plasmon dispersion theory. The wavelength of the dominant surface plasma wave is large compared to the size of the discontinuities, so the effect of the thin film should be the same as that of a continuous film whose thickness is the average thickness of the discontinuous film. On this basis, the thicknesses of several silver sulfide films are calculated from the measured frequency shift of the resonance peak and are found to be in excellent agreement with values determined from independent ellipsometric measurements.

© 1970 Optical Society of America

Optical Constants of Silver Sulfide Tarnish Films*

J. M. Bennett, J. L. Stanford, and E. J. Ashley
J. Opt. Soc. Am. 60(2) 224-232 (1970)

Reflectance and Ellipsometry When Submicroscopic Particles Bestrew a Surface*

Dwight W. Berreman
J. Opt. Soc. Am. 60(4) 499-505 (1970)

Validity of Ellipsometry for Determining the Average Thickness of Thin, Discontinuous, Absorbing Films*

H. E. Bennett, D. K. Burge, R. L. Peck, and J. M. Bennett
J. Opt. Soc. Am. 59(6) 675-681 (1969)

Surface-Plasmon Effect in the Reflectance of a Metal*†

Julian Crowell and R. H. Ritchie
J. Opt. Soc. Am. 60(6) 794-799 (1970)

Ultraviolet Optical Constants of Thin Films Determined by Reflectance Measurements

G. Baldini and L. Rigaldi
J. Opt. Soc. Am. 60(4) 495-498 (1970)