The Extreme Values of Reflectivity and the Conditions for Zero Reflection from Thin Dielectric Films on Metal

The equations for the film thickness necessary to achieve the maximum and minimum values of reflectivity and the conditions for zero reflection for systems with one or two dielectric films over a metallic substrate are derived. Extension of results to multilayer systems are made on the basis of simple relationships obtained for the single- and double-layer systems in order to improve the effectiveness and the practical applicability of the systems. A simple system requiring an impractical value for film thickness or refractive index can be substituted by an equivalent symmetric multilayer system consisting of films with optical parameters within practical range of use.