Photrefractive Polymer-Based Holographic Data Storage

Photorefractive materials promise to enable dynamic holography and erasable high density data storage for future information technologies. This project will develop and demonstrate a holographic data storage technology using novel photorefractive polymers with electro-optic (EO) coefficients and bandwidths that are significantly superior than LiNbO3. An important advantage of these polymers is that large refractive index modulations can be reversibly generated in them with low power laser beams. Polymer composites based on poly(N-vinylcarbazole) have recently show excellent PR performance. However, the composites in their natural form lack long-time storage capabilities due to their low glass transition temperatures. This project innovatively overcomes this limitation by engineering highly cross-linked, permanently poled PR polymers. This will enable relatively low cost, long life holographic data storage technology. The program's technical approach is to orient acrylated EO chromophores in the liquid phase at room temperature with an electric field and to cross-link the material with electron radiation in a vacuum environment. The proposed method promises to be superior to previous approaches to permanently poled PR polymers and will enable the fabrication of materials with low weight, excellent mechanical properties, strong polar orientation and superior thermal aging characteristics. During Phase I, we will establish proof-of-concept of the holographic data technology in the photorefractive polymers; during Phase II material and product performance will be optimized and extensively tested. The technology is expected to play a key role in a variety of optical information processing applications; e.g. dynamic holography, erasable high density data storage, parallel signal/image processing, phase conjugation, pattern recognition, optical interconnects and others.