Recent Trends in Holographic Optical Storage Technology with Special Emphasis on Photorefractive Recording Materials

Abstract

In this paper, the fundamental framework and developments of holographic optical memory, recent progress in system implementation and recording materials have been reviewed. The optical storage technology has matured to the level of achieving a fast transfer rate exceeding 10⁹ bits/s. The major development in photorefractive recording materials is the two-color recording in LiNbO₃, which supersedes the longstanding issue of destructive readout. It has been realized that near-stoichiometric LiNbO₃ is promising to tailor multi-energy levels owing to the reduced non-stoichiometric defects in this material.