Introduction to photonic crystals and metamaterials

Photonic crystals have the fundamental characteristic of manipulating light at a scale on the order of the wavelength or even shorter. This property allows to develop new functional devices for a wide range of applications. PhCs have been investigated, both theoretically and experimentally, for telecom devices and sensing because of their peculiar properties, such as the capability of realizing high Q-factor cavities, enhancing field-matter interaction and controlling the group velocity. In this chapter the basic physics of photonic crystals, with specific reference to the origin of the photonic band gap, and their main applications are reviewed. A brief description of fundamentals of metamaterials and their applications is also reported in the chapter.