Thin film coatings: algorithms for the determination Of reflectance and transmittance, and their derivatives.

The paper deals with the specular optical properties of thin dielectric or metallic multilayer coatings. Recurrent formulas are given for reflectance, transmittance, and their derivatives with respect to thicknesses, indices, incidence, and wavelength. Because of its simplicity and flexibility, the proposed method is particularly well fitted for use in a digital computer and for optimization programs.