Sol−Gel Organic−Inorganic Composites for 3-D Holographic Lithography of Photonic Crystals with Submicron Periodicity

We demonstrate that silica−acrylate materials doped with transition metal (Zr, Ti) oxide nanoparticles are suitable for the three-dimensional holographic lithography of photonic crystals with submicron periodicity and large inorganic contents. By careful choice of inorganic components, such composites could provide a route to the template-free, direct lithography of three-dimensionally ordered structures with high refractive-index contrast, submicron periodicity, and band gaps in the visible and infrared regions.