Acrylate dendritic monomers for fabricating holographic data storage media with high performance

Photopolymer is well-recognized as an ideal holographic data storage medium. In order to improve the holographic performance of a two-stage photopolymer, five acrylate dendritic monomers (DM-1/2/3/4/5) with high refractive indices (1.590-1.634) are designed and synthesized in this study. Their structures are characterized by 1H NMR, 13C NMR, FTIR and HR-MS spectra, and their photopolymerization kinetics are investigated through real-time FTIR. Using these DMs as one recording monomer, a series of photopolymer samples with different formulations are fabricated. The influence of DM-1/2/3/4/5 on the holographic performances of these samples are explored under holographic exposure of a 532 nm laser. The results show that the photosensitivity and angle selectivity of these samples can be improved by adding these DMs. The most excellent holographic characteristics are obtained by a sample with 4% DM-1. Using it as a data storage medium, a volume holographic grating with high diffraction efficiency of 90% and narrow selection angle of 0.11 degrees is recorded. Moreover, the sample achieves a high dynamic range of 13.7 and a low volume shrinkage of 0.36% after recording 60 holograms through angular-multiplexing with low record/read exposure dose, indicating its great application potential in holographic data storage.