Photosensitive composition for volume hologram recording

A photosensitive composition for volume hologram recording used for recording an interference fringe produced by the interference of laser beams or lights having excellent coherence as a fringe with a different refractive index, said composition comprising the components as follows:

• (a) a radical polymerizable compound represented by the formula:
• ##STR4## wherein R.sub.1 and R.sub.2 is a terminal radical polymerizable group bonded to the phenyl ring of the diarylfluorene skeleton through at least one oxyethylene chain, oxypropylene chain, urethane group or amide group, and X.sub.1 to X.sub.4, respectively, indicate H, (C.sub.1 -C.sub.4) alkyl group, (C.sub.1 -C.sub.4) alkoxy group, amino group, dialkylamino group, hydroxyl group, carboxyl group or halogen atom:
• (b) a cationic polymerizable compound having compatibility with component (a);
• (c) a radical photopolymerization initiator which is sensitized to a laser beam having a specific wavelength or light having a specific wavelength and excellent coherence to polymerize the component (a);
• wherein an average refractive index of the component (a) is larger than that of the component (b);
• and
• (d) a cationic photopolymerization initiator having low photosensitivity to light having a specific wavelength, which is sensitive to light having a different wavelength to polymerize the component (b).