A New Class of Photopolymer for Holographic Data Storage Media Based on Organometallic Matrix

摘要

New photopolymer materials were prepared with a view to achieving holographic data storage media of large dynamic range. For this purpose, organometallic compounds of high refractive index were used as a matrix, and organic compounds as photosensitive monomers. The organometallic matrix was obtained from transition metal- and silicon-alkoxides by modifying the sol-gel process. The matrix was combined with low refractive index monomers, and then the mixture was filled between glass substrates to fabricate recording media. These media showed M-number (M/#) of about 42 to 64 (per 1 mm thickness) when evaluated by a plane-wave tester equipped with a 407 nm laser diode. As for the sample which gave M/# of approximately 42, a raw data density of 76 Gbit/in.~2 was achievable upon multiplex page-data recording by a coaxial optical system, in which a page-data volume was 56.8 kbit/page. In another experimental result, optimization of monomer structures brought about a shrinkage ratio of 0.08% as a mechanical volume change.