Simple computations involving two-component symmetric trilayers

The equivalent properties of a symmetric three-layer structure are derived by a nontraditional method that provides useful insights and a simplified application to some thin-film design problems. The equations derived from this method may be used to design a three-layer replacement for a single layer in an interference coating. The equations are especially helpful for cases that involve complex numbers, such as metal layers or above-critical angle propagation in dielectric layers. Several multilayer design problems are solved to demonstrate the application of this approach. (C) 2002 Optical Society of America.