Fast Bits Recording in Photoisomeric Polymers by Phase-Modulated Femtosecond Laser

High storage capacity and recording-access rate are two critical factors that the current optical storage technology pursues. Efforts on shortening the laser wavelength, increasing the numerical aperture of objective, and increasing the optical drive speed have been made to reach this end. However, these methods have run their full course because of many existing difficulties on the physical and manufacturing aspect. People have to explore innovative ways to satisfy the requirement of both mass data and high rate. Multidimensional optical storage and holographic recording are two promising technologies to increase the capacity of memory and recording rate by orders of magnitude. We report on the fast bits recording in bisazobenzene functional polymer film by femtosecond laser holographic recording. The mechanism of the photo-induced anisotropy of the material is reviewed and discussed. The demonstration of multidimensional holographic recording is presented. Some influence factors in the holographic processing are discussed.