Organic/inorganic hybrid materials were prepared by synthesizing from titanium tetraisopropoxide (TTIP), diethanolamine (DEOA), and water. Formulating the materials with thermosetting polymers, the composites were designed for refractive optical contacts with heat lamination of a film having >50 mu m thickness. Inherent difficulties of TiO(2) and sol-gel reaction of TTIP, i.e. photocatalytic properties and prompt sol-gel reaction to form large TiO(2) particle, were avoided by stabilizing Ti with use of DEOA. The reactivity of the sol-gel reaction and formation of TiO(2) crystal structure were suppressed by DEOA. However, suppression of the photocatalytic properties was not enough and needed a use of anti-oxidant agent, 2,6-di-t-butyl-p-cresol (BHT). The titanium-based organic/inorganic hybrid materials and its epoxy composites were transparent in visible wavelength region and gave in the range of 1.66 to 1.73 of refractive indices depending on stoichometric parameters of TTIP, water, and DEOA for the hybrid materials. POLYM. ENG. SCI., 51: 1636-1641, 2011. (C) 2011 Society of Plastics Engineers