DETERMINATION OF OPTICAL CONSTANTS OF POLYMER FILMS THROUGH REFLECTION

The transmittance values measured in IR specular external reflection (RS) or internal reflection (ATR) spectra can be used to determine the optical constants of solid surfaces or dielectric films laid on solid substrates. To obtain the optical constants of polystyrene films laid on steel we used Kramers-Kronig analysis. In this case, the optical constants are obtained from IR external reflection spectrum recorded at a single incidence angle. The transmittance measured and the phase shift angle obtained by Kramers-Kronig integral, are used in this case. Using Kramers-Kronig analysis offers the advantage of processing a large volume of data. Keywords: Reflection-absorption, optical constants, IR spectra, Kramers-Kronig analysis, dispersion analysi