THE DETERMINATION OF THICKNESS AND OPTICAL
CONSTANTS FOR POLYMETHYL METHACRYLATE FILM
FROM IR REFLECTANCE SPECTRA
The transmittance values measured in IR reflection-absorption (RA)
spectra can be used to determine the optical constants of dielectric films laid on
solid substrates. When the recorded spectra show interference fringes, one can
determine the film thickness. The film thickness was obtained from the
reflexion-absorption IR spectra recorded at two different incidence angles.
To obtain the optical constants of polymethylmetacrilat films laid on
steel we used dispersion analysis. Using dispersion analysis offers the
advantage of processing a large volume of data.
Keywords: reflection absorption, optical constants, IR spectra,
dispersion analysis
Cuvinte cheie: reflexie-absorbţie, constante optice, spectre IR, analiza
de dispersie
