Mesoscopic photonic crystals made of TiO2 hollow spheres connected by cylindrical tubes

The face-centered cubic (fcc) photonic crystals of titanium dioxide (TiO2) hollow spheres connected by TiO2 cylindrical tubes have been fabricated using silica template. The preparation process is based on the vertical deposition method, thermal sintering and selective etching techniques. In the crystal, the lowest energy pseudogaps at points U and K of the Brillouin zone have been opened.