Investigations of Switchable Mesoscale Lattices for Photonics

用于光子学的可切换介观尺度晶格的研究

• 批准号: 0322878
• 负责人: Gregory Crawford
• 金额: $ 25.5万
• 依托单位: Brown University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2003
• 资助国家: 美国
• 起止时间: 2003-09-01 至 2007-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0322878&HistoricalAwards=false
• 关键词: Investigations; Switchable; Mesoscale; Lattices; Photonics

0322878CrawfordThis proposal focuses on discovery and application of two- and three-dimensionally structured holographically formed polymer dispersed liquid crystals (H-PDLC) for the creation of electrically switchable mesoscale lattices targeted at photonic crystal (PhC) and diffractive optical applications. H-PDLC materials exhibit fast switching (100 ms), low absorption in the visible and near IR, high diffraction efficiency, tunable refractive index profiles, and simple and inexpensive one step fabrication. Holographic-lithography at 351 nm or 532 nm is proposed to generate optical lattices that are permanently captured in holographic-polymer dispersed liquid crystals through a photo-diffusion phase-separation process. The PI will perform temporal multiplexing exposure techniques to mimic nature and build artificial lattices. One such lattice, which has been shown to exhibit lasing, is known as the liquid crystal blue phase (BP). The BP is stable on the temperature scale between the helical cholesteric phase and the isotrophic phase, where a highly ordered 3D lattice is found. Other proposed lattice configurations include the diamond lattice, superimposed lattices, quasilattices, and superlattices, with investigations focusing on their application potential (e.g. lasing, waveguides, strain-gauges). By cooperating with the local Chapters of the Women in Science and Engineering (WiSE) and the National Society for Black Engineers (NSBE), the research findings can be broadly disseminated to underrepresented groups in science and engineering through forums and presentations. In addition, a module will be created for K-12 students and teachers to demonstrate how lattices self organize, and to integrate lattice formation with art for younger children. A conference will be organized on photonics and entrepreneurship at Brown University to bring together faculty, industry, students, and the investment community to show university researchers how to potentially create value out of their basic photonics research.

Crawford该提案集中于二维和三维结构的全息形成的聚合物分散液晶（H-PDLC）的发现和应用，用于创建针对光子晶体（PhC）和衍射光学应用的电可切换介观晶格。 H-PDLC材料表现出快速开关（100 ms），在可见光和近红外低吸收，高衍射效率，可调折射率分布，和简单和廉价的一步制造。提出了在351 nm或532 nm处的全息光刻，以产生通过光扩散相分离过程在全息聚合物分散液晶中永久捕获的光学晶格。 PI将执行时间复用曝光技术，以模仿自然并构建人工晶格。 一种这样的晶格，已被证明表现出激光，被称为液晶蓝相（BP）。 BP在螺旋相和各向同性相之间的温度范围内是稳定的，在那里发现了高度有序的3D晶格。其他提出的晶格构型包括金刚石晶格、叠加晶格、准晶格和超晶格，研究集中在它们的应用潜力（例如激光、波导、应变计）上。 通过与当地科学和工程妇女分会（WiSE）和全国黑人工程师协会（NSBE）合作，研究成果可以通过论坛和演讲广泛传播给科学和工程领域代表性不足的群体。 此外，还将为K-12学生和教师创建一个模块，以演示晶格如何自我组织，并将晶格形成与年幼儿童的艺术相结合。 布朗大学将组织一次关于光子学和创业精神的会议，将教师、工业界、学生和投资界聚集在一起，向大学研究人员展示如何从基础光子学研究中创造价值。