Investigation of the humidity influence on optical properties of chitosan thin films by spectroscopic ellipsometry

This work is devoted to the theoretical analysis of the inverse problem of ellipsometry. This problem for many years remained one of the most important tasks in the study of thin films while interest in the ellipsometric measurements stimulated by the possibility of obtaining planar fiber structures of various shapes and finding new materials, technologies and applications. This paper presents a theoretical apparatus for solving the inverse problem of ellipsometry, various methods of determining the optical parameters of the investigated thin films. Experimentally various samples of chitosan thin films on glass substrate were investigated by spectroscopic ellipsometer “Ellipse 1891 SAG” using the developed mathematical models. As it was revealed, a jump of refraction indexes at various humidity in the measured environment was observed, that does the given material perspective for creation on its basis of new planar optical waveguides in the future.