Attenuated-total-reflection technique for the determination of optical constants

In a glass-metal-dielectric system, it is normally impossible to determine simultaneously the complex dielectric constant, the thickness of the metal, and the corresponding parameters of a dielectric overlayer. We propose the use of the pseudo-Brewster or Abelés angle as an additional parameter to characterize simultaneously a dielectric thin-film overcoating and the metal surface parameters. We use a Kretschmann attenuated-total-reflection configuration. An admittance diagram is used to illustrate graphically the role of an absentee layer at this angle. A study of the limitations of the method is also presented.