An epoxy-functional inorganic-organic hybrid material system for use in photonic waveguiding applications was synthesised by the sol-gel method. The influence of preparation process parameters such as composition and UV irradiation, on the properties of the deposited thin films was studied. Crack-free films with thickness up to 37 mu m were obtained from a single-step deposition process. A tunable refractive index, at 633 nm, which ranged between 1.480 and 1.515 was observed by modifying the concentration of the refractive index modifier. It was also demonstrated that UV irradiation resulted in an increase in the refractive index of the system by 0.49%. Planar waveguiding structures were demonstrated. A high thermal stability, up to 275 degrees C, was achieved compatible with post-processing integration processes. (C) 2006 Elsevier B.V. All rights reserved.