Direct analysis of monomer diffusion times in polyvinyl/acrylamide materials

We propose an alternative, direct method to calculate monomer diffusion times in photopolymer materials. Very long period gratings are recorded in the photopolymer, and the real time variation in diffraction efficiency due to monomer diffusion is then analyzed. In photopolymers, monomer diffusion plays a fundamental role in hologram formation. However, since many interrelated parameters affect hologram formation, the usual techniques do not allow for an independent estimation of monomer diffusion times. The direct method proposed is applied to two polyvinyl based photopolymers with different molecular weights.