Cavity Enhanced Ultrafast Transient Absorption Spectroscopy

腔增强超快瞬态吸收光谱

• 批准号: 1404296
• 负责人: Thomas Allison
• 金额: $ 40.5万
• 依托单位: SUNY at Stony Brook
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-08-15 至 2018-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1404296&HistoricalAwards=false
• 关键词: Cavity; Enhanced; Ultrafast; Transient; Absorption

In this project funded by the Chemical Measurement and Imaging Program of the Chemistry Division, Professor Thomas K. Allison and his research group at Stony Brook University will develop ultrafast laser techniques for studying the motions and reactions of molecules in very dilute gas phase samples. The basic approach involves what is called an optical resonant cavity, which will greatly increase the sensitivity of the laser based measurements. This new technique will be applied to understanding the basic photochemistry of how molecules move when they are excited by light, and how they dispose of this excitation energy.This project concerns the development and implementation of new techniques for performing femtosecond time-resolved spectroscopy using frequency comb lasers and high-finesse optical resonators. A large sensitivity improvement over traditional methods extends the capabilities of all-optical ultrafast spectroscopies, such as broad-band transient absorption spectroscopy and 2D optical spectroscopy to dilute gas phase samples produced in molecular beams. This enables the study of ultrafast dynamics of isolated molecules and small clusters of molecules, including designer molecular systems produced in cold supersonic expansions in vacuum. Initial studies will focus on ultrafast internal conversion in isolated gas phase systems with visible chromophores and also micro-solvated systems (e.g. a cluster containing the molecule of interest and a few solvent molecules). Extension of the techniques to the mid-IR to study the vibrational dynamics of small hydrogen bonded clusters will elucidate cooperative effects in hydrogen-bonded liquids.

在这个由化学部化学测量和成像项目资助的项目中，托马斯·K·艾利森教授和他在石溪大学的研究小组将开发超快激光技术，用于研究非常稀的气相样品中分子的运动和反应。 基本方法涉及所谓的光学谐振腔，这将大大提高基于激光的测量的灵敏度。 这项新技术将用于了解分子在光激发时如何移动的基本光化学，以及它们如何处理这种激发能量。该项目涉及使用频率执行飞秒时间分辨光谱的新技术的开发和实施梳状激光器和高精细光学谐振器。与传统方法相比，灵敏度大幅提高，扩展了全光学超快光谱的能力，例如宽带瞬态吸收光谱和二维光谱，可稀释分子束中产生的气相样品。这使得能够研究孤立分子和小分子簇的超快动力学，包括在真空中冷超音速膨胀中产生的设计分子系统。初步研究将重点关注具有可见发色团的隔离气相系统以及微溶剂化系统（例如包含感兴趣分子和一些溶剂分子的簇）中的超快内部转换。将技术扩展到中红外以研究小型氢键团簇的振动动力学将阐明氢键液体中的协同效应。