ABSTRACT
Diffraction gratings, interference filters, and multilayer dielectric mirrors are some examples of periodic structures. This chapter considers a number of common diffraction principles in periodic structures. Diffraction is a phenomenon that is connected with waves of any nature such as electromagnetic waves or material waves. This phenomenon consists in the deviation of wave propagation near obstacles. For the precise calculation of a diffraction pattern, it is necessary to solve Maxwell’s equations with boundary conditions. The simplest description of diffraction is based on the Huygens–Fresnel principle, according to which each point of a wave front becomes a source of secondary spherical wave. The chapter discusses the properties of photonic crystals which can be divided into 1D, 2D, and 3D photonic crystals depending on whether the refractive index varies periodically in one, two, or three spatial directions. It also includes exercise problems related to diffraction of waves in periodic structures.
