Diamond-Structure Photonic Crystals Composed of Ceramic Spheres in Resin and Their Microwave Properties
Three-dimensional (3D) photonic crystals with a diamond structure composed of TiO2 ceramic spheres in a resin matrix were fabricated by stereolithography. The lattice constant was 12 mm. The diameter of the spheres was about 5 mm. These photonic crystals composed of ceramic spheres showed four complete photonic band gaps at around 5.7 GHz between the 2nd and 3rd bands, 7.8 GHz between the 8th and 9th bands, 10.4 GHz between the 24th and 25th bands, and 13.1 GHz between the 54th and 55th bands. The propagation characteristics of microwaves propagating through the photonic crystals agreed well with the calculated results using the plane-wave expansion method.