Dynamic hologram recording characteristics in DuPont photopolymers

Hologram formation and diffusion reactions in photopolymer films are examin ed at different stages of exposure and at different spatial frequencies. Di fferent properties of the grating formation process are evaluated from effi ciency data, including the relative rates of diffusion and photoinitiated p olymerization, dye absorption, and residual efficiency enhancement after UV curing. It was also found that gratings with larger periods (similar to 1. 4 mu m) are susceptible to erasure effects with postexposure laser illumina tion. In addition, crossed gratings were found to have an extended dynamic range. This effect can have a significant impact on the number of holograms formed with rotational or peristrophic multiplexing. (C) 1999 Optical Soci ety of America. OCIS codes: 090.2900, 090.4220, 050.1950, 160.5470.