Planar photonic crystals move toward wider use

Photonic crystals are formed by etching or constructing 2-D or 3-D arrays of shaped structures into a dielectric medium. Although by no means confined to the optical regime, when fabricated with submicron dimensions, these arrays form the optical analogy of a semiconductor material, which means that photons are either allowed or nanallowed states of the lattice depending on their energy. Here, Charlton et al discuss the development of planar photonic crystals devices, which has benefited from several advances, exhibiting significant promise for real applications and production line.