Infrared ellipsometry of nanometric anisotropic dielectric layers on absorbing materials

•The inversion problem of infrared ellipsometry is resolved on the basis of a fresh mathematical approach.•The novel method possesses very high sensitivity because it is founded only on the phase conversion measurements.•The method is successfully applicable for nanometric layers in the infrared spectral region.

An inversion problem of infrared ellipsometry is resolved on the basis of a fresh mathematical approach, which does not use the traditional regression analysis for data handling and has no need of initial guesses for the desired parameters. It is shown that obtained simple analytical equations for ellipsometric quantities open up new possibilities for determining optical parameters of an anisotropic ultrathin layer. The novel method possesses very high sensitivity because it is based on the phase conversion measurements of polarized reflected light. The method is tested using a numerical simulation and the results demonstrate clearly that it is successfully applicable for nanometric layers in the infrared spectral region.