Nonlinear Spectroscopy: Absorption and Refraction

非线性光谱：吸收和折射

• 批准号: 0524533
• 负责人: Eric Van Stryland
• 金额: $ 24万
• 依托单位: The University of Central Florida Board of Trustees
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2005
• 资助国家: 美国
• 起止时间: 2005-09-01 至 2009-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0524533&HistoricalAwards=false
• 关键词: Nonlinear; Spectroscopy; Absorption; Refraction

0524533Van StrylandThis project studies the spectra of nonlinear optical (NLO) absorption and the dispersion of NLO refraction in a variety of materials types including classes of organic materials, nanocrystalline semiconductors and nanoparticles coupled to organic materials. The ultimate goals are to build a database of NLO properties of materials provided by researchers from around the world which, through collaboration with theorists, will lead to a predictive capability for these nonlinear processes that will also allow the determination of structure/NLO property relations. The PI has developed the experimental facilities for NLO materials characterization spanning a very large spectral (from the UV to 18mm) and temporal range (from femtosecond to nanoseconds). One of the workhorse tools that he has developed is a femtosecond pump/continuum probe, nonlinear "spectrophotometer" which measures the frequency nondegenerate NLO absorption spectrum along with its temporal response (critical for applying causality to determine Kramers-Kronig relations for the NLO refraction). The temporal response is useful for determining the source of the NLO response. In addition, he has very recently developed a "White-Light-Continuum Z-scan" (WLC Z-Scan). This method utilizes the broad spectrum of a femtosecond continuum pulse to directly measure the degenerate nonlinear absorption and separately measure the dispersion of the nonlinear refraction over a broad spectral range in a single experiment. The degenerate nonlinearities are often the ones of interest for applications, and this will allow for checks on the predictions of Kramers-Kronig relations. Intellectual merit: The experimental methodologies will provide a very large jump in the information database available for developing and understanding the fundamental bases for NLO interactions in multiple materials and material types. With this expanded database, observed trends will lead to scaling relations which lead to validation and/or modification of theory. At the same time this information provides feedback to materials researchers as to methods to enhance (or diminish) nonlinear responses.Broader impacts: This project will partially fund the training of three Ph.D. students (2 on NLO and one in organic synthetic chemistry) as well as several undergraduate students through the NSF Research Experiences for Undergraduates program. An additional graduate student, funded through Co-PI Hagan's NSF GK-12 program, will work with teachers in local schools on the development of Optics content in the 9th grade science curriculum. The curricula of two graduate optics courses (Fundamentals of Optical Science and Nonlinear Optics) have been enriched by incorporation of information from this work.

本项目研究非线性光学（NLO）吸收光谱和NLO折射色散在各种材料类型中，包括有机材料、纳米晶体半导体和与有机材料耦合的纳米颗粒。最终目标是建立一个由来自世界各地的研究人员提供的材料的NLO特性数据库，通过与理论家的合作，将导致这些非线性过程的预测能力，也将允许确定结构/NLO特性关系。PI开发了NLO材料表征的实验设施，涵盖了非常大的光谱（从紫外到18mm）和时间范围（从飞秒到纳秒）。他开发的主要工具之一是飞秒泵浦/连续介质探针，一种非线性“分光光度计”，用于测量非简并NLO吸收光谱的频率及其时间响应（对于应用因果关系来确定NLO折射的Kramers-Kronig关系至关重要）。时间响应对于确定NLO响应的来源是有用的。此外，他最近还开发了一种“白光连续z轴扫描”（WLC z轴扫描）。该方法利用飞秒连续脉冲的广谱直接测量简并非线性吸收，并在单次实验中在广谱范围内分别测量非线性折射的色散。退化的非线性通常是应用中感兴趣的非线性，这将允许对Kramers-Kronig关系的预测进行检查。智力优势：实验方法将为开发和理解多种材料和材料类型的NLO相互作用的基本基础提供非常大的信息数据库跳跃。有了这个扩展的数据库，观察到的趋势将导致缩放关系，从而导致理论的验证和/或修改。同时，这些信息为材料研究人员提供了增强（或减少）非线性响应的反馈。更广泛的影响：本项目将通过NSF本科生研究经验项目部分资助3名博士生（2名NLO和1名有机合成化学）和几名本科生的培训。另外一名研究生，由Hagan的国家科学基金GK-12项目资助，将与当地学校的教师一起开发9年级科学课程中的光学内容。两门研究生光学课程（光学科学基础和非线性光学）的课程因纳入了这项工作的信息而变得更加丰富。