EXISTENCE OF A PHOTONIC GAP IN PERIODIC DIELECTRIC STRUCTURES

Using a plane-wave expansion method, we have solved Maxwells equations for the propagation of electromagnetic waves in a periodic lattice of dielectric spheres (dielectric constant a) in a uniform dielectric background (b). Contrary to experiment, we find that fcc dielectric structures do not have a photonic band gap that extends throughout the Brillouin zone. However, we have determined that dielectric spheres arranged in the diamond structure do possess a full photonic band gap. This gap exists for refractive-index contrasts as low as 2. © 1990 The American Physical Society.