Development of Synthesis, Processing, and Characterization Techniques for Next Generation Electroactive Materials

9818179 dalton将开展两个领域的研究活动：(1)设计和合成与电光调制、光学放大和传感器保护相关的新型聚合物电活性材料；(2)开发和利用新形式的光谱学，以改进材料电活性的表征。第一个研究领域包括发展改进的理论，能够预测电活性聚合物的超分子组装和组织，利用这种理论指导合成含有发色团的聚合物材料，这些材料可以通过适当的处理（例如，在聚合物玻璃转变温度附近的电场极化），产生具有大电光活性的材料。开发新的晶格硬化化学反应来锁定加工引起的电光活性，以及使用这种聚合物材料制造集成“光芯片”，即将超大规模集成电路半导体电子器件与聚合物电光调制器电路集成。对超分子（纳米级）结构的控制也将扩展到其他技术上重要的聚合物体系的开发，包括含有电活性树状聚合物材料的稳定聚合物材料。同样，新的理论设计概念将应用于开发具有受控纳米级分子组织和受控分子间电子相互作用的材料。聚合物加工将用于实现实际（最终商业化）实施所生产的材料所需的最终材料特性。在第二个研究重点领域，将特别关注飞秒光谱新技术的发展，这与电活性聚合物材料的表征特别相关。其中包括改进“瞬时”光学非线性测量的技术，这对于理解各种宏观光学非线性的大小和理解材料响应时间都是必要的。特别地，重点将放在发展新技术的频率敏捷，近简并，多波混合光谱和开发“信号晶格”检测方案，允许同时测量各种光学非线性的实分量和虚分量。从这些技术中获得的信息将用于评估新材料在各种实际光子应用中的适用性。研究还将定义分子的光化学稳定性，并将提供与光收集等过程相关的激发态能量转移的细微之处的基本见解。以前NSF支持的研究已经产生了新的最先进的电信和信号处理聚合物电光调制器（PEOM）设备，其特点是带宽大于100 GHz，驱动电压要求小于5伏（数字电压水平），总插入损耗约为4dB。这样的调制器很可能是未来信息高速公路的关键组件，也可用于各种光网络中的信号检测、平板显示器、有线电视、雷达应用、制导系统、信息处理和信号路由。聚合物调制器目前正被评估为下一代高带宽互联网通信的组成部分。以类似的方式，改进的光纤放大和白光收集材料已经开发出来，这对光纤通信有重要的改善。这项工作产生的非常基本的理论认识可能会对固体和液态材料的科学认识产生深远的影响，并可能为纳米级结构控制材料的合成和由这种组织衍生的特殊性能提供重要的指导

9818179DaltonTwo areas of research activity will be pursued: (1) The design and synthesis of new polymeric electroactive materials relevant to electro-optic modulation, optical amplification, and sensor protection; and (2) the development and utilization of new forms of spectroscopy that permit improved characterization of material electroactivity. The first area of research includes the development of improved theory capable of predicting the supramolecular assembly and organization of electroactive polymers, the use of such theoretical guidance to synthesize chromophore-containing polymer materials that can, with appropriate processing (e.g., electric field poling near the polymer glass transition temperature), produce materials exhibiting large electro-optic activity, the development of new lattice hardening chemical reactions to lock-in processing-induced electro-optic activity, and the use of such polymeric materials for the fabrication of integrated "opto-chips", i.e., integrating VLSI semiconductor electronics with polymeric electro-optic modulator circuitry. Control of supramolecular (nanoscale) architecture will also be extended to the development of other technologically important polymeric systems including stable polymer materials incorporating electroactive dendrimer materials. Again, new theoretical design concepts will be applied to develop materials with controlled nanoscale molecular organization and controlled intermolecular electronic interactions. Polymer processing will be used to achieve final material properties necessary for practical (ultimately commercial) implementation of materials produced. In the second area of research focus, particular attention will be given to the development of new techniques of femtosecond spectroscopy that are particularly relevant for the characterization of electroactive polymeric materials. These include techniques for improved measurement of "instantaneous" optical nonlinearities necessary for understanding both the magnitude of various macroscopic optical nonlinearities and necessary for understanding materials response times. Particularly, focus will be given to development of the new technique of frequency-agile, near-degenerate, multiple-wave-mixing spectroscopy and exploitation of the "signal-lattice" detection scheme that permits simultaneous measurement of the real and imaginary components of various optical nonlinearities. Information from these techniques will be used to evaluate the appropriateness of new materials for various practical photonic applications. Studies will also define photochemical stability of molecules and will provide fundamental insight into subtleties of excited energy transfer relevant to processes such as light harvesting.%%%Previous NSF supported research has resulted in new state-of-the-art telecommunication and signal processing polymeric electro-optic modulator (PEOM) devices characterized by bandwidths of greater than 100 GHz, drive voltage requirements of less than 5 volts (digital voltage levels), and total insertion losses on the order of 4dB. Such modulators are likely to be critical components of future information superhighways as well as being used for signal detection, flat panel displays, CATV, radar applications, guidance systems, information processing, and signal routing in a variety of optical networks. Polymeric modulators are currently being evaluated as components of next generation high bandwidth internet communication. In like manner, improved fiber optical amplification and white light harvesting materials have been developed that promise important improvement in fiber optic communication. Very fundamental theoretical understanding resulting from this work will likely have far ranging impact on the scientific understanding of solid and liquid state materials and will likely provide important guidance for the synthesis of materials with architectural control at the nanometer level and special properties derivative from such organization.***