Organic materials for UV holographic and digital storage

We demonstrate the possibility of photodimerizable chromophores attached to a short alkyl chain as a potential medium for high capacity digital optical storage. A large increase in transmission from 4% to 70% is obtained in 20 s when irradiated with a 5 mW unfocused laser beam at 257 nm in a thin film of 1-(6-Bromohexyl)uracil. Through theoretical simulations, we show that the interaction cross-section is 6 10-18 cm2 at a photon dose of 9 1016 photons cm-2 s-1. We also investigate the formation of holographic diffraction grating in a film, obtaining an efficiency of 16%, mainly due to a surface relief grating.