Photorefractive Materials for Optical Signal Processing

Real time thin film holographic elements are crucial components in a number of optical signal processing technologies. There is a need for development of materials to record both permanent and reconfigurable holograms. Recently, polymeric photorefractive (PR) materials have evoked a lot of interest as inexpensive holographic media. This Phase I project proposes to develop anew class of polymeric PR materials. The materials proposed are soluble polydiacetylenes (PDAs), known to exhibit large charge carrier mobilities and high photoconductivity. These polymers will be asymmetrically functionalized with second order nonlinear optical (NLO) chromophores and urethane containing flexible side groups. Polymer chains of these novel asymmetric PDAs self-assemble in an acentric stable polar organization leading to second order optical nonlinearities. High photoconductivity and large mobility, in conjunction with the NLO properties, would result in the fast PR response in these materials. These polymers will be synthesized and processed into thin films and bulk samples. Materials will be characterized for their optical properties, photoconductivity, and charge carrier mobility. PR measurements will be carried out to evaluate the PR responses of the materials. The polymeric PR materials would yield inexpensive and efficient holographic recording media. Such materials have applications in the areas of optical signal processing, optical data storage, and holographic optical interconnects. Also, such materials are suited for devices in industrial control and automation, based on real-time optical interferometry.