Photonic Crystals

Photonic crystals are novel structures which are characterized by periodic variation of dielectric permittivity in space. Optical propertiles of photonic crystals are very different from usual media. Due to periodicity in space, propagation of light inside a photonic crystal resembles the propagation of electrons in a periodic crystal lattice. As a result, electromagnetic waves in photonic crystals have band structure. There is a possibility of bandgap formation, where propagation of light is forbidden independently of polarization and direction. This unique feature of photonic crystals opens the door of possible revolutionary discoveries in telecommunication, physics of laser, superconductors and other areas.

There are already optical filters produced based on photonic crystals, as well as waveguides which are smaller and characterized with less losses compared to optical fiber. Application of such a waveguides is possible not only in telecommunication but in healthcare, where photonic crystals have already proven to be useful in life saving applications. It is possible to create lasers based on photonic crystals with a lower laser threshold; materials with negative refractive index which open a possibility to focus a light in a spot smaller than a wavelength. It also was used to manufacture a flexible display with wide spectral range, where each pixel represents a photonic crystal - a specially ordered array of silicon microspheres. Photonic crystals might enter our life in the near future, when technology will allow their massive and cheap production.