Optical transmittance and reflectance and dynamic current density for thin metallic films

Abstract

Formulas for reflection and transmission coefficients R and T for electromagnetic radiation in thin metallic films are given, where the anomalous skin effect and electron scattering at the film boundaries are taken into account. The equations are valid in the near-infrared, visible, and ultraviolet spectral range, and at low frequencies where the skin effect is nearly classical. The classical size effect in the optical absorption for different values of the specularity parameters is considered. The observed oscillatory nature of the absorptance provides a promising method for verifying the boundary conditions for the free electrons at the film surfaces. Finally, a generalized Fuchs formula for the dynamic current density is developed, which is valid in the same frequency ranges as R and T.