Holographic nanocomposites for recording polymer-nanoparticle periodic structures: II. Mechanism of formation of polymer-nanoparticle bulk periodic structure and effect of parameters of forming field on structure efficiency

We considered the mechanism by which bulk periodic structures are formed in polymer-nanoparticle nanocomposites. Phase bulk gratings are formed due to the diffusion transfer of nanoparticles between illuminated and nonilluminated regions of a composite upon polymerization in an interference field. We found that, for the majority of studied nanocomposites containing nanoparticles of different natures, the relative modulation of the concentration of nanoparticles exceeds 80%. We showed that the initial composition should be optimized with respect to the mass of nanoparticles, which ensures a maximal recording efficiency at a minimal level of light scattering in the grating. We found that, for each medium, there exist optimal recording conditions (the intensity and period of the field) under which n (1) is determined only by the parameters of the medium and does not depend on the parameters of the field. Examples of the practical use of periodic structures based on developed holographic nanocomposites are given.