ИСТИНА

In this paper, the results of investigation of optical properties of structured (discretely or continuously) thin (much thinner than the wavelength) films are discussed. The derived analytical expressions allow one to determine the effective refractive index and effective optical thickness of the structured films with an arbitrary periodical or aperiodical spatial profile of the refractive index. It is shown that optical properties of such films have a number of invariant properties with respect to the shape of the spatial dependence of the refractive index. Analytical algorithms for the reconstruction of the refractive index spatial dependence profile and measuring the optical thickness of the structured films based on their reflection characteristics are suggested.