RUI: Phase Stability and Chromophore Reorientation in Photorefractive Polymer Composites

该RUI项目致力于光折变高分子材料的研究，重点是具有适当非线性光学响应的新型发色团的合成和表征，并寻求确定低Tg（玻璃化转变温度）光折变聚合物中相稳定性和发色团重取向之间的关系。 与非线性光学染料分子共混的光折变聚合物由于染料的空间重取向而表现出相对大的折射率调制。 由德鲁大学化学和物理系的学生和教师组成的跨学科团队将通过合成具有相对相似光学特性但与主体聚合物相互作用显著不同的染料分子来制造跨越一系列材料行为的光折变聚合物。每种复合材料的相稳定性将通过测量随时间变化的光吸收系数来观察。折射率调制将通过衍射效率测量来确定，并且染料的相对取向迁移率将通过依赖于频率的透射椭圆偏振法来推断。这些数据将被用来描绘相稳定性/取向迁移率权衡的边界，并提高对染料-聚合物相互作用的理解和适用于应用的共混物的设计。该计划的一个重要特点是通过在一个基本和技术上重要的领域对学生进行培训来整合研究和教育。所有的材料制造和光学特性将发生在德鲁大学的化学和激光实验室。这些实验室已经开发的部分通过NSF-ILI授予“材料科学和非线性光学在物理和化学实验室”，并代表了一个正在进行的努力，将非线性光学材料的制造和表征与德鲁本科教学实验室。这些实验是桌面规模的，让学生接触到雇主和研究生院所重视的光子和电子技术。学生们也将有机会通过首席研究员和G博士的合作，研究他们制造的材料的全息图像存储特性。陆军研究实验室的伍德这项研究对本科生来说是智力上的，让他们在工作中有一种主人翁感。该RUI奖将在三年内支持六名暑期研究生，并将在学年期间为荣誉和独立研究项目提供设备支持。结果将在同行评议的研究文献与学生合著者传播，并在专业会议上提出。***

This RUI project addresses photo-refractive macromolecular materials research with emphasis on the synthesis and characterization of new chromophores with appropriate non-linear optical response, and seeks to identify the relationship between phase stability and chromophore reorientation in low-Tg (glass transition temperature) photorefractive polymers. Photorefractive polymers blended with nonlinear optical dye molecules exhibit relatively large refractive index modulations due to spatial reorientation of the dye. An interdisciplinary team of Drew University students and faculty from the Chemistry and Physics departments will fabricate photorefractive polymers spanning a range of materials behavior by synthesizing dye molecules of relatively similar optical properties but considerably different interactions with the host polymer. The phase stability of each composite will be observed through measurements of the time dependent optical absorption coefficient. The refractive index modulation will be determined by diffraction efficiency measurements, and the relative orientational mobility of the dyes will be inferred through frequency dependent transmission ellipsometry. This data will be used to delineate boundaries of the phase-stability/orientational-mobility tradeoff, and to improve understanding of dye-polymer interactions and the design of blends suitable for applications.%%% An important feature of the program is the integration of research and education through the training of students in a fundamentally and technologically significant area. All of the materials fabrication and optical characterization will occur at Drew University in chemistry and laser laboratories. These laboratories have been developed in part through an NSF-ILI grant "Materials science and nonlinear optics in physics and chemistry laboratories" and represent an ongoing effort to integrate the fabrication and characterization of nonlinear optical materials with Drew undergraduate instructional labs. The experiments are tabletop in scale and expose students to the photonic and electronic technology valued by employers and graduate schools. Students will also have the opportunity to study the holographic image storage properties of the materials they fabricate through a collaboration between the principal investigator and Dr. G. Wood of the Army Research Lab. The research is intellectually accessible to undergraduates, giving them a sense of ownership in their work. This RUI award will support six summer research students over three years, and will provide equipment support for Honors and Independent Study projects during the academic year. Results will be disseminated in peer-reviewed research literature with student co-authors and presented at professional meetings. ***