<title>Randomly addressable read/write/erase holographic memory system based on a dye-polymer recording medium</title>

Abstract

With a potential of up to 1012 bits/cm3, storage medium based on volume holographic memory can be the next generation of optical memory systems. However, any storage media for holographic memory must have large reflective index modulation, large available volume material while simultaneously preserving high response speed and low crosstalk. Photorefractive crystals, such as LiNbO3, SBN, and BaTiO3, are the most popular materials for the 3-D memory medium candidates. However, they possess low refractive index modulation, very small available volume, low response speed, and poor optical quality. They also exhibit low multiplexing capability, low diffraction efficiency, and high cross talk. These are the main difficulties for the application of photorefractive materials for holographic memory. Organic materials are of high nonlinearity, easy processing, and great cost-effectiveness. They may overcome the problems with photorefractive crystals. In this paper, an erasable dye polymer memory medium is exploited for a randomly addressable read/write/erase holographic memory system. To our knowledge, this is the first demonstration of an erasable holographic memory system. The system has 100 pages of memory. Its read/write speeds are mainly limited by the input spatial light modulator/output detector array. Although being 2-D, it can be potentially developed into a 3-D system.