Holographic data storage is considered as the one of the next generation information storage technologies because of its potential in high storage capacity and fast read out speed. Holographic recording makes it possible to store several gratings in the same position by multiplexing. Progress in the last few years has been very impressive, in the field of photopolymers that offer a wide variety of recording mechanisms including both write-once and rewritable media.Optimization and further development of photopolymer media will be the key to success of this and other advanced optical storage...