Abstract The polymer poly{1-[2′-methyl-4′-(2″-methylphenylazo) phenylazo]-2-( m -methacryloyloxyoctyloxy}naphthalene, where m = 6, 8, 10, is synthesized by free radical addition polymerization method for holographic optical data storage. Characterization of the polymers is done by formation of the holographic grating. A study of the dependence of diffraction efficiency of the grating formed on various parameters is presented. Surface relief gratings on these polymer films are created upon exposure to argon ion laser beams at 514.5 nm without any subsequent processing steps. The surface structure of the relief gratings has been investigated by atomic force microscopy. The depth of surface relief in a typical case is found to be around 40 nm.