Band-structure properties of one-dimensional photonic crystals under the formalism of equivalent systems

Some general properties of one-dimensional photonic crystals are analyzed by using symmetric periodic multilayers. In this way a one-dimensional photonic crystal can be considered a single thin film with an equivalent optical admittance and an equivalent phase thickness. These functions provide important information about the optical properties of the photonic crystal, such as the band structure and the characteristic points, where the bandgaps narrow and close, including Brewster points, which are all determined by analytic expressions. With this formalism it is also possible to study in a simple way different kinds of surface modes that can be present at the interface between photonic crystal and bulk material.