SBIR Phase II: Novel Polymeric Photorefractive Materials for Optical Image Processing

*** 9510017 Li本小企业创新研究二期项目将开发基于共轭聚合物的实用聚合物光折变材料，用于光学图像处理。提出的研究重点是设计、合成和加工具有大光学非线性、高光电导率和大载流子迁移率的共轭聚合物基光折变材料。第一阶段的结果表明，具有非线性光学官能团的聚噻吩基共轭聚合物可以表现出光折变效应。测量了大双光束耦合（TBC）增益系数。在第一阶段的基础上，第二阶段的研究将集中于增强共轭聚合物基材料的光折变特性。提出了几种提高材料电光系数和光电导率的方法。此外，共轭聚合物中固有的大载流子迁移率有望提供优于当前存在的聚合物光折变材料的优势。这些共轭材料将以其线性光学和NLO性质、光电导率以及载流子迁移率来表征。通过TBC和简并四波混频（FWM）实验来研究材料的光折变特性。这些新型材料有望在速度和灵敏度上超过目前报道的聚合物光折变材料。为了证明新型光折变材料在信息存储和图像处理中的应用，将在这些材料上进行全息图像记录和检索实验。实用聚合物光折变材料的发展将为波导光折变技术提供一种廉价而高效的全息记录介质，应用于实时图像处理、高密度光学数据存储、全息光学互连、联想记忆、相位共轭、光学非相干到相干转换器和光束转向等领域。此外，这种材料适用于基于实时光学干涉测量的工业控制和自动化设备。＊＊＊

*** 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. ***