Abstract
Ideally ordered TiO2 hole arrays with high aspect ratios were prepared by the anodization of pretextured Ti. The obtained TiO2 acted as two-dimensional photonic crystals in which a photonic band gap is formed in all directions of light propagation in the lattice. The process allows the easy and low-cost fabrication of TiO2 photonic crystals and can be used for the preparation of functional optical devices, which require the precise control of light propagation. (C) 2016 The Japan Society of Applied Physics