We synthesized a novel photoresponsive monomer, silicon-containing azo monomer with paired mesogens in the side chain, by reacting 3-methacryloxypropyl-methyldichlorosilane with 2-[2-(4-cyano-azobenzene-4'-oxy)ethylene-oxylethyl alcohol, a mesogenic group. Corresponding homopolymer and copolymers with methyl methacrylate were generated via radical polymerization with AIBN as a radical initiator. Investigations of their thermal properties and optical textures confirmed the monomer and the homopolymer have smectic structures. Homo- and copolymer films showed high potential as reversible data recording media via photoinduced alignment of azobenzene groups with irradiation of a linearly or circularly polarized light. Out of all the samples, the copolymer films with high azo dye contents showed the best resolution in the recorded data as well as the fastest response to a pump beam due to large optical birefringence induced in a write-in process. Strong dependence of the stability of the data stored in the films on the glass transition temperature of the polymers was also observed. In addition, high-quality holographic grating patterns were inscribed even on the copolymer film with azo molar content of only 7.0% using a modified two-wave mixing technique. (c) 2008 Wiley Periodicals, Inc.