Original Entry: Ian Bruce Burgess Fall 2009
A photonic crystal is a dielectric superlattice whose refractive index varies periodically in three dimensions. The simplest type of photonic crystal is a single-component dielectric with high refractive-index which has a periodic lattice of air holes. With sufficiently high refractive index-contrast, the lattice forbids the propagation of light in all direction over a specific frequency range. This range is called the photonic crystal's band gap.