利用飞秒时间分辨CARS光谱研究分子内超快动力学与火焰测温

项目名称： 利用飞秒时间分辨CARS光谱研究分子内超快动力学与火焰测温

项目编号： No.61275157

项目类型： 面上项目

立项/批准年度： 2013

项目学科： 无线电电子学、电信技术

项目作者： 夏元钦

作者单位： 哈尔滨工业大学

项目金额： 78万元

中文摘要： 基于飞秒时间分辨相干反斯托克斯拉曼散射(CARS)光谱不仅可以得到分子内部诸如激发态布居数的变化、电子运动、原子核振动、分子结构和振动模式信息，还能够通过驰豫过程和温度得到分子种类和密度等参数信息，为探测分子内飞秒量级的超快分子动力学信息提供了一个新的手段；同时由于可以减少或排除时间零点之外非共振极化信号的影响而使得飞秒时间分辨CARS光谱在燃烧场温度、成分浓度测量精度方面大大提高。本项目拟利用2.6mJ/30fs激光及其泵浦的两台光学参量放大器(OPA)激光器，以气相、液相、固体晶体分子及火焰为样本，开展分子内基态和激发态电子波包动力学、分子相干振动态的弛豫和失相过程以及拉曼振动模选择激发和振动模之间的能量传递过程等超快动力学信息研究，同时开展飞秒时间分辨CARS光谱对于2500K以内的火焰燃烧场的温度、成分浓度测量的理论和实验研究。

中文关键词： 飞秒激光脉冲；时间分辨；相干反斯托克斯拉曼散射光谱；超快动力学；燃烧测温

英文摘要： Femtosecond time-resolved coherent anti-Stokes Raman scattering (CARS) spectroscopy presents ultrafast intramolecular dynamics such as the change in excited state population, electronic motion, nuclear vibration, molecular structure and vibration mode information. Species and density of molecular parameters can be gained from the relaxation process and tempreture, which provides a new method for detection of ultrafast intramolecular dynamics. Measurement precision of flame tempreture and species concentration would be greatly increased due to elimination of the nonresonant signal in femtosecond time-resolved CARS spectroscopy. In this project 2.6mJ/30fs femtosecond laser and two optical parametric amplifiers(OPA), gas, solid(crystal), liquid phase molecules and flame as samples are used. Ultrafast intramolecular dynamics such as wave packet dynamics of electronic ground and excited states, relaxation and dephasing process of molecular vibration state, selective-excitation Raman vibration mode and energy transfer process between vibration modes will be investigated. Measurement of tempreture and species concentration for flame below 2500 K will also be theoretically and experimentally studied by using femtosecond time-resolved CARS spectroscopy.

英文关键词： Femtosecond laser pulse；Time-resloved；Coherent anti-stokes Raman Spectroscopy；Ultrafast dynamics；Flame thermometry