NSF Award
9510017
*** 9510017 Li This Small Business Innovation Research Phase II project will develop practical polymeric photorefractive materials based on conjugated polymers for optical image processing. The proposed research will focus on design, synthesis, and processing of conjugated polymer-based photorefractive materials with large optical nonlinearities, high photoconductivity and large charge carrier mobilities. The results obtained from Phase I demonstrated that polythiophene-based conjugated polymers with nonlinear optical (NLO) functionalities can exhibit the photorefractive effect. Large two beam coupling (TBC) gain coefficient has been measured. Based on the Phase I effort, the Phase II research will concentrate on the enhancement of the photorefractive properties of conjugated polymer-based materials. Several approaches are proposed to boost up the electro-optic coefficients and the photoconductivity of the materials. In addition, the intrinsically large charge carrier mobilities in the conjugated polymers are expected to provide an edge over currently existing polymeric photorefractive materials. These conjugated materials will be characterized for their linear optical and NLO properties, photoconductivity, as well as the charge carrier mobility. TBC and degenerate four wave mixing (FWM) experiments will be carried out to study the photorefractive properties of the materials. These novel materials are expected to surpass the polymeric photorefractive materials so far reported both in speed and sensitivity. To demonstrate the application of the novel photorefractive materials for information storage and image processing, holographic image recording and retrieval experiments will be performed on these materials. Development of practical polymeric photorefractive materials would yield an inexpensive and efficient holographic recording medium for waveguide photorefractive technologies, with applications in the areas of real-time image processing, high-density optical data sto rage, holographic optical interconnects, associative memories, phase conjugation, optical incoherent to coherent converters and beam steering. Also, such materials are suited for devices for industrial control and automation, based on real-time optical interferometry. ***
