partnership between light and matter

Photonic crystals are periodic dielectric structures with an index of refraction periodicity of the order of the wavelength of light. They are emerging as a key building block for many applications in nanotechnology that involve controlling the flow of light. In this paper, the basic physical principles and applications of photonic crystals are presented, as well as descriptions of some of the many chemical and physical strategies that have been used for their fabrication. (Some figures in this article are in colour only in the electronic version) 1