New acrylamide-based photopolymers with poly(methyl methacrylate-co-methacrylic acid) as a polymer matrix were prepared and their optical properties including diffraction efficiency and optical transparency were investigated. As the content of methacrylic acid unit was increased, the phase stability of photopolymer was enhanced, while the diffraction efficiency decreased. The enhancement in phase stability is explained in terms of miscibility enhancement between the polymer matrix and photopolymerizable components, and the decrease in diffraction efficiency is mainly attributed to the inhibition of diffusion of acryl amide probably due to the hydrogen bonding induced between polymer matrix and acrylamide with the increase of the acid content. (c) 2006 Elsevier B.V. All rights reserved.