Figure 10.

(a) A 3D PhC comprised of close packed spheres (the opal structure). A cubic lattice is represented by a red box. (b) Wigner-Seitz cell of the fcc latice showing the BZ boundaries. Two paths of wavevectors are represented in red and blue lines for the 3D band diagrams. (c) A 3D PhC made by inversion of the close packed fcc structure (the inverse opal structure). (d) A 3D photonic band diagram of the opal structure made of silicon (n = 3.5). The partial gap along [111] direction (Γ-L) is represented in a red gap. (e) A 3D photonic band diagram of the inverse opal structure made of silicon (n = 3.5). A wider partial gap (a red gap) along [111] direction (Γ-L) and a complete gap (a green gap) between 8th and 9th bands are shown.