Fourteen university, government, and industrial laboratories prepared a total of twenty pairs of single-layer titanium dioxide films. Several laboratories analyzed the coatings to determine their optical properties, thickness, surface roughness, absorption, wetting contact angle, and crystalline structure. Wide variations were found in the optical and physical properties of the films, even among films produced by nominally the same deposition techniques.
The refractive index of a layer is a sensitive function of the preparation conditions. Normal incidence measurement of the optical properties can reveal possible inhomogeneity of index. We propose a method of automatic determination of the complex refractive index and thickness of a layer which includes systematic measurement of the degree of inhomogeneity which is represented by a simple model. The usefulness of the technique is demonstrated by examples that form part of an experimental study of a number of useful optical materials including Y(2)O(3), TiO(2), MgF(2), HfO(2), and SiO(2). The dispersions of the refractive index, the extinction coefficient, and of the inhomogeneity are represented by Cauchy formulas with accurately determined coefficients. The results can therefore be readily used in computing the optical properties of thin-film multilayers.
The calculated spectral transmittance of a multilayer laser mirror is used to determine the effective index of the single layer equivalent to the multilayer stack. We measure the artificial anisotropy of photoresist thin films whose structure is a one-dimensional, subwavelength grating obtained from interference fringes. The limitation of the theory of the first-order effective index homogenization is discussed. We designed normal-incidence, polarizing coating and a polarization rotator by embedding anisotropic films in simple multilayer structures.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations –citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.