This work is devoted to photoresponsive hybrid organic-inorganic materials prepared by the sol-gel method, using dithienylethene or azobenzene as photosensitive chromophores. These photochromic units were covalently attached to the silica backbone as part of the main-chain and as a side group respectively. The electrocyclization of dithienylethene or the isomerization of azobenzene under irradiation cause local modifications of the optical properties of the host sol-gel polymers We took advantage of either high refractive index changes (>10(-2)) or material deformation of the sol-gel films to design optical components and to store information.