A discussion of the characteristics of a self-developing, photopolymerizable material for non-transient hologram recording with high diffraction efficiency

Some characteristics of a photopolymerizable holographic recording material which has been developed in our laboratory are presented for discussion. The material consists of two monomers, an electron donor, a sensitising dye and a polymer binder in which the other components are contained. The material has many advantages over more conventional recording materials, the most significant one being the ability to self-process. This property in particular makes the material highly suitable for various holographic techniques including the fabrication of DOEs. Refractive index modulation occurs within the material due to the photo-induced polymerisation of monomer in exposed regions. The extent of this refractive index modulation is thought to be influenced by the rate at which the reactants diffuse into the light exposed areas. Some diffusion studies have been carried out in order to examine this in more detail. The results are presented for discussion. Experimental parameters, for example, beam intensity and beam ratio were varied in order to obtain Bragg curves for recorded gratings. These are a highly effective means of obtaining important information about the material. It will be shown that the results from characterisation studies provide valuable information about the material with particular relevance to the fabrication of DOEs.