基于阶梯镜和超连续白光的单脉冲泵浦-探测光谱技术

项目名称： 基于阶梯镜和超连续白光的单脉冲泵浦-探测光谱技术

项目编号： No.11304242

项目类型： 青年科学基金项目

立项/批准年度： 2014

项目学科： 数理科学和化学

项目作者： 闫理贺

作者单位： 西安交通大学

项目金额： 30万元

中文摘要： 飞秒时间分辨泵浦-探测技术是研究分子超快动力学过程的重要手段。在光化学、光物理反应等不可逆过程研究中，由于反应物耗尽、生成物累积等因素影响，传统的飞秒泵浦-探测技术面临种种困难。为此，本项目提出一种基于阶梯镜和超连续白光的实时泵浦-探测光谱技术，该技术可实现在单个飞秒-皮秒脉冲时间内完成具有时间-波长分辨的二维图谱测量，同时还具有时间分辨率高、动态范围大等优点。本项目主要研究内容包括：通过研究飞秒泵浦-探测测量中自衍射等相干效应的抑制技术，提高泵浦-探测的信噪比；通过研究飞秒激光诱导超连续白光产生及其传输过程中的啁啾特性的量化与调控技术，提高测量系统的时间分辨率和信噪比；研制基于阶梯镜和超连续白光的时间和波长二维分辨的单脉冲泵浦-探测测量系统，系统的时间分辨率优于200 fs，测量动态范围在亚皮秒~数百皮秒内可调。

中文关键词： 飞秒激光；超连续白光；泵浦-探测光谱技术；超快成像；

英文摘要： Femtosecond time-resolved pump-probe is an important tool to investigate the molecular ultrafast dynamics. In some irreversible processes such as photochemistry and photophysical reactions, however, the traditional pump-probe technique is not suitable due to the exhaustion of the reactants and the accumulation of the resultants. In this project, we propose a real-time pump-probe spectroscopy technique based on echelon and supercontinuum generation. This method allows real-time two-dimensional mapping of wavelength- and time-resolved transient spectrum using a single femtosecond to picosecond laser pulse, which has a high time-resolution and large dynamic measurement range. The study includes: (1) Investigating the mechanism of some coherent effect in the pump-probe measurements and improving the signal-to-noise ratio of the measurements by eliminating the influence of self-diffraction effect. (2) Improving the time-resolution and the signal-to-noise ratio of the pump-probe measurements by investigating the method of the stable and uniform supercontinuum generation, and the characterization and control technique of its chirp character in the transmission process. The final goal is to exhibit a single-shot pump-probe spectroscopy measurement system with time and wavelength resolution based on echelon and super

英文关键词： femtosecond laser；supercontinuum；pump-probe technique；ultrafast iamging；