2002 Volume 110 Issue 1281 Pages 391-394
Two-dimensional (2D) photonic crystals (PCs) of transparent TiO2 gel rods, with a diameter in the range of 0.5 to 2.0μm, arrayed in a triangular lattice with a lattice constant between 1.0 and 4.0μm, were successfully fabricated from a titanium tetra-isopropoxide (Ti(OiPr)4) ethylene glycol monomethyl ether (EGMME) solution using resist molds. The resist molds were fabricated on a Si wafer by electron-beam lithography. By casting the solution into the resist molds, we obtained TiO2 gel PCs, which contained polyethylene glycol (55-60 mass%) used as a plasticizer, formed on gel plates with the same composition over an area of 500μm×500μm. This method enabled the preparation of dense, highly transparent TiO2 gel PCs. Distinct changes in both reflected and transmitted colors were observed in the present gel PCs, demonstrating that they function as photonic crystals in the visible region.