Observation and control of ultrafast surface photochemistry

任何化学分支的最终目标，包括表面化学，都是在基础水平上理解反应。为了实现这一点，既需要在原子长度尺度上观察反应，也需要在与断键和成键相同的时间尺度上监测反应-飞秒时间尺度(1 fs=10-15 S)。随着扫描探针显微镜的出现，在原子长度尺度上观察表面反应几乎已成为常规。然而，以飞秒的精度观测表面反应的动力学仍然是一个相当大的挑战。这项提案将解决这个问题。它的目的是通过使用最先进的飞秒泵浦-探测技术实时监测反应，为理解表面过程的详细动力学奠定基础。它还将研究利用整形飞秒激光脉冲控制表面光化学的可能性，这一可能性在理论上讨论已久，但尚未在实验上实现。如果这种控制技术成功，将会产生巨大的影响，并将对我们理解表面反应过程做出很大贡献。通过将伦敦大学学院化学系内两个独立的、历史悠久的研究小组聚集在一起，组成一个独特的团队，在表面科学和超快激光技术方面拥有必要的实验专业知识，研究计划将成为可能。

The ultimate goal of any branch of Chemistry, including surface Chemistry, is to understand reactions at a fundamental level. In order to achieve this, it is necessary to both observe the reaction on an atomic length scale, and also to monitor the reaction on the same time scale as bond breaking and making - the femtosecond timescale (1 fs = 10-15 s). With the advent of scanning probe microscopy, the observation of surface reactions at the atomic length scale has become almost routine. However, observing the dynamics of surface reactions with femtosecond accuracy still remains a considerable challenge. This proposal will address this issue. It aims to establish the foundations for understanding the detailed dynamics of surface processes, by using state-of-the-art femtosecond pump-probe techniques to monitor reactions in real time. It will also investigate the possibility, long discussed theoretically but not yet achieved experimentally, of using shaped femtosecond laser pulses to control surface photochemistry. If this control technique is successful it will have a huge impact and will contribute greatly to our understanding of surface reaction processes. The programme of research will be made possible by bringing together two independent well-established research groups within the UCL Chemistry department to form a unique team with the necessary experimental expertise in both surface science and ultrafast laser technology.