Photonic Band Gaps in 3D Network Structures with Short-range Order
  We present a systematic study of photonic band gaps (PBGs) in three-dimensional (3D) photonic amorphous structures (PAS) with short-range order. From calculations of the density of optical states (DOS) for PAS with different topologies, we find that tetrahedrally connected dielectric networks produce the largest isotropic PBGs. Local uniformity and tetrahedral order are essential to the formation of PBGs in PAS, in addition to short-range geometric order. This work demonstrates that it is possible to create broad, isotropic PBGs for vector light fields in 3D PAS without long-range order. 
Seng Fatt Liew, Jin-Kyu Yang, Heeso Noh, Carl F. Schreck, Eric R.   Dufresne, Corey S. O'Hern and Hui Cao
physics.optics cond-mat.mtrl-sci