Examination of the photoinitiation processes in photopolymer materials

Holographic data storage requires multiple sequential short exposures. However, the complete exposure schedule may not necessarily occur over a short time interval. Therefore, knowledge of the temporally varying absorptive effects of photopolymer materials becomes an important factor. In this paper, the time varying absorptive effects of an acrylamide/polyvinylalcohol photopolymer material are examined. These effects are divided into three main photochemical processes, which following identification, are theoretically and experimentally examined. These processes are (i) photon absorption, (ii) photosensitizer recovery, and (iii) photosensitizer bleaching.