Photo-responsive properties of azobenzene small molecules in sol-gel hybrid TiO₂/ormosil organic-inorganic matrices

Azodye-doped TiO₂/ormosil hybrid materials for photonic applications were prepared by a low temperature sol-gel process from an organic-inorganic hybrid system. Acid-catalyzed solutions of γ-glycidoxypropyltrimethoxysilane and methyltrimethoxysilane mixed with tetrapropyl orthotitanate were used as hybrid matrix precursors. The trans-cis-trans photoisomerization of azobenzene small molecules in sol-gel hybrid organic-inorganic matrices was induced by a photoirradiation with UV light and subsequent visible light. It was found that the hybrid film doped with azodyes and heated at a lower temperature was much better for applications in optical storage or optical switch. The planar waveguide properties of the hybrid films were also investigated by using a prism coupling technique. These results indicates that it is possible for the as prepared hybrid films to allow directly integrating on the same chip the optical storage or optical switch devices with the pump source.