Embedded channel waveguides formed on a z-cut erbium-doped lithium niobate (Er:LiNbO3) substrate by a high-energy ion implantation technique are first described. A
In this article we present a method to determine the band spectrum, band gaps, and discrete energy levels, of a one-dimensional photonic crystal with localized impurities. For one-dimensional crystals with piece wise constant refractive indices we develop an algorithm to recover the refractive index distribution from the period map. Finally, we derive the relationship between the period map and the scattering matrix containing the information on the localized modes.