Method to control the optical parameters of thin transparent films using angle optical reflectometry

A way is suggested to determine the thickness and refractive index of films on an optically homogeneous substrate from the angular dependence of the intensity of $H$-polarized probing radiation reflected from the film. It is found that there is an angle at which a family of reflection curves taken of transparent films with the same refractive index and different thicknesses intersect (become degenerate). The tangent of this angle equals the refractive index of the film. The efficiency of this method is demonstrated with a series of BSN/MgO(001) films.