Evolution of the higher order band structure in FCC photonic crystals

Abstract

Summary form only given. Recently, several groups have reported inverted opals that may satisfy the requirements for a complete photonic band gap (PBG). These photonic crystals, which represent a face-centered cubic (FCC) lattice of spherical voids in a high refractive index material, were made from materials with sufficiently high refractive index to open the PBG. However, a fundamental question remains about how the intrinsic disorder present in opal photonic crystals will affect the PBG. Deviations in the lattice constant, point defects in the lattice, and the tendency to form stacking faults during the self-assembly of inverted opals, results in significant inhomogeneous broadening of the stop-bands and eventually can eliminate the PBG. We report quantitative measurements of the higher frequency photonic band structure in opal photonic crystals in the region of the eighth and ninth bands. These bands should evolve toward the complete PBG with increase of the refractive index contrast.