Relief holograms recording on liquid photopolymerizable layers

The formation mechanisms of relief holograms in liquid photopolymerizable layers are analyzed and noted to involve monomer diffusion from darker to lighter areas. The relief depth obtained increases monotonically with initial layer thickness. After gelation in highlighted areas, the mobility of polymer molecules becomes limited by network bounds and monomer-polymer interdiffusion ceases, so that only monomer diffusion into the gel can restore thermodynamic equilibrium.