Sol-gel derived titania/γ-glycidoxypropyltrimethoxysilane and methyltrimethoxysilane hybrid materials for optical waveguides

We report here on titania/organically modified silane hybrid materials produced by the sol-geli technique for optical waveguide applications. Acid catalyzed solutions of γ-glycidoxypropyltrimethoxysilane and methyltrimethoxysilane mixed with tetrapropylorthotitanate have been used as precursors for the hybrid materials. Waveguide films with a thickness about 1.3-μm have been prepared on a silicon substrate by a single-coating process and low-temperature heat treatment. Atomic force microscopy (AFM), thermal gravimetric analysis (TGA), UV-visible spectroscopy (UV-VIS), and Fourier transform infrared (FTIR) spectroscopy have been used to investigate the optical and structural properties of these waveguide films. The results have shown that dense, pore-free, and highly transparent films can be obtained by low temperature heat treatment. The planar waveguide propagation loss of the hybrid films has also been measured.