Ellipsometry is a non-destructive method for analyzing optical constants of bulk materials and thin films. In the case of thin layers, it can determine the thickness of the layer in a wide range from nanometer to micrometer thicknesses with an accuracy of units of Angstrom. Variable angle IR-VASE ellipsometer Woollam operated in the infrared and far infrared range of the spectrum covering the wavelengths from 1,7 to 30 μm.