Strong Field Molecular Ionization With Shaped Ultrafast Laser Pulses

这项工作将促进我们对电子在分子中如何运动的理解。电子在原子、分子和固体中的运动发生在阿秒（十亿分之一秒的十亿分之一）的时间尺度上，需要非常短的激光脉冲来分辨。这个项目的研究人员将使用超强的超短激光脉冲来使分子电离，去除与分子结合的众多电子中的一个。他们将利用一种称为速度图成像的技术，拍摄电子从分子中脱离出来的照片。这些图像可以用来了解电离过程中的电子动力学，这对分子成像、化学动力学和新型高速电子学的发展具有重要意义。本项目将利用形状少周期激光脉冲研究小分子的强场电离。研究人员将利用超快光脉冲整形和速度图成像来研究角和动量分辨光电子能谱与激光脉冲形状的关系。这将有助于我们理解电子是如何从多个轨道中移除的，以及电子相关和非玻恩奥本海默动力学在电离动力学中发挥作用的程度。研究人员还将利用强场电离作为激发态动力学的探针，研究相似分子家族的解离和内部转化。

This work will advance our understanding of how electrons move in molecules. The motion of electrons in atoms, molecules and solids takes place on attosecond (a billionth of a billionth of a second) timescales, and requires very short laser pulses to resolve. The investigators in this project will use intense ultrashort laser pulses in order to ionize molecules, removing one of the many electrons bound to the molecule. They will take pictures of the electrons as they come off the molecules, making use of a technique called velocity map imaging. These pictures can be used to understand electron dynamics during ionization, which is important for molecular imaging, chemical dynamics and the development of new high speed electronics. This project will make use of shaped few cycle laser pulses to study strong field ionization of small molecules. The investigators will make use of ultrafast optical pulse shaping of filament based sub 10 fs (3-4 optical cycles) laser pulses, as well as velocity map imaging in order to study the angle and momentum resolved photoelectron spectrum as a function of laser pulse shape. This will help develop our understanding of how electrons are removed from multiple orbitals, and the extent to which electron correlation and non-Born Oppenheimer dynamics play a role in the ionization dynamics. The investigators will also make use of strong field ionization as a probe of excited state dynamics, studying dissociation and internal conversion in families of similar molecules.