Study of Optical Properties of Glass-Like Polymer Material for Blue Laser Holographic Optic Data Storage Recording

Holographic data storage is the most promising data storage technology in the next generation due to the advantages of the ultra-high data storage density and high data transfer rate. Dimensional stability of storage media and photorefraction effect of the grating are the two most important factors for holographic storage. In this study, a blue laser holographic material with low shrinkage is developed. The organic-inorganic hybrid matrix is triethoxysilylpropyl polyethyleneglycol carbamate (TSPEG) homogeneously bonded with tetraethyl orthosilicate (TEOS) prepared by sol-gel method. Diallyl phthalate pre-polymer (DAPP) and 9,10-Phenanthrenequinone (PQ) were used as a monomer and a photoinitiator, respectively. Optical data recording was performed by a blue laser source with a wavelength of 405 nm and the intensity of laser is 2 mW/cm². The photoinduced free radical polymerization of DAPP in the presence of PQ can be initiated by the blue laser irradiation. The inorganic backbone limits the shrinkage resulting from the polymerization and increases the rigidity of the matrix. The shrinkage measurement shows that the blue laser holographic material with TSPEG/TEOS=0.2 (molar ratio) has very low shrinkage of about 0.145% after recording the hologram.