Determination of the Optical Constants and Thickness of a Highly Absorbing Film Using the Attenuated Total Reflection Technique

Theoretical analysis of the Kretschmann configuration for attenuated total reflection experiments shows that near the critical angle the reflectivity is strongly dependent upon the dielectric constants and thickness of a thin absorbing layer on the prism surface. Numerical calculations based on Fresnel's equations illustrate this clearly for thin absorbing films. Using this property of highly absorbing films it has then been possible to determine the optical constants of a thin film of phthalocyanine over the visible region of the spectrum.