Department of Physics, Swansea University, Swansea, SA2 8PP, UK.
Faraday Discuss. 2011;153:343-60; discussion 395-413. doi: 10.1039/c1fd00042j.
The use of strong-field (i.e. intensities in excess of 10(13) Wcm(-2)) few-cycle ultrafast (durations of 10 femtoseconds or less) laser pulses to create, manipulate and image vibrational wavepackets is investigated. Quasi-classical modelling of the initial superposition through tunnel ionization, wavepacket modification by nonadiabatically altering the nuclear environment via the transition dipole and the Stark effect, and measuring the control outcome by fragmenting the molecule is detailed. The influence of the laser intensity on strong-field ultrafast wavepacket control is discussed in detail: by modifying the distribution of laser intensities imaged, we show that focal conditions can be created that give preference to this three-pulse technique above processes induced by the pulses alone. An experimental demonstration is presented, and the nuclear dynamics inferred by the quasi-classical model discussed. Finally, we present the results of a systematic investigation of a dual-control pulse scheme, indicating that single vibrational states should be observable with high fidelity, and the populated state defined by varying the arrival time of the two control pulses. The relevance of such strong-field coherent control methods to the manipulation of electron localization and attosecond science is discussed.
我们研究了使用强场（即强度超过 10(13) Wcm(-2)）的少周期超快（持续时间为 10 飞秒或更短）激光脉冲来创建、操纵和成像振动波包。通过隧道电离对初始叠加进行准经典建模，通过通过跃迁偶极子和斯塔克效应非绝热地改变核环境来修改波包，以及通过分子的碎裂来测量控制结果，详细介绍了这种方法。详细讨论了激光强度对强场超快波包控制的影响：通过修改成像的激光强度分布，我们表明可以创建焦点条件，使这种三脉冲技术优先于仅由脉冲引起的过程。本文提出了一个实验演示，并讨论了准经典模型推断的核动力学。最后，我们提出了一种双控制脉冲方案的系统研究结果，表明应该可以用高保真度观察到单个振动状态，并可以通过两个控制脉冲的到达时间来定义填充状态。讨论了这种强场相干控制方法对电子定位和阿秒科学的操纵的相关性。
