Ellipsometric Characterization of Surface Quality for Polished Optical Glass Using Maxwell-Garnett Model in the Effective Medium Approximation

Ellipsometry is a technique of surfaces analysis, founded on the measure of light polarization state after reflection on a flat surface. The present work consists in characterizing the surface quality of polished optical glass by ellipsometry and use of effective medium model. The measured ellipsometric parameters enabled us to obtain a correlation with surface roughness on the base of the theory of Maxwell-Garnett assuming an effective medium layer of effective thickness de and refractive index ne. Observations by Nomarski microscope made it possible to confirm the results obtained.