Strong-Field Physics with Mid-IR Fields
Strong-Field Physics with Mid-IR Fields
复制标题
DOI：
10.1103/physrevx.5.021034
复制
发表时间：
2015-06-26
影响因子：
12.5
通讯作者：
Biegert, Jens
中科院分区：
文献类型：
--
作者：
Wolter, Benjamin;Pullen, Michael G.;Biegert, Jens
强场物理学目前正经历向使用中红外驱动波长的转变。这是因为它们允许在准静态范围内明确地进行实验，并且能够利用与电子碰撞的有质动力标度有关的效应。在中红外进行的初始测量立即导致了对光电离的更深入的理解，并允许在不同的理论模型之间进行区分。重散射的有质动力标度已经为分子结构的时间分辨探测开辟了新的途径。这一范式转变的关键是两种实验工具的融合：（1）强中红外光源，可以在准静态范围内产生高能光子和电子;（2）探测系统，可以探测产生的高能粒子，并在完全重合的情况下对整个相互作用的动量空间进行成像。在这里，我们提出了这两个基本成分，即160 kHz的中红外光源和反应显微镜检测系统的独特组合，提出了一种实验方法，提供了一个前所未有的三维视图强场相互作用。该系统能够产生和检测跨越6个数量级动态范围的电子能量。我们证明了系统的多功能性，通过调查电子的电子电离，驱动强场现象的核心过程，在低（meV）和高（数百eV）的能量。低能区用于研究最近发现的低能结构，而高能电子用于通过激光诱导电子衍射探测原子结构。此外，我们提出，第一次，相关的动量分布的电子从非顺序双电离驱动的中红外脉冲。
Strong-field physics is currently experiencing a shift towards the use of mid-IR driving wavelengths. This is because they permit conducting experiments unambiguously in the quasistatic regime and enable exploiting the effects related to ponderomotive scaling of electron recollisions. Initial measurements taken in the mid-IR immediately led to a deeper understanding of photoionization and allowed a discrimination among different theoretical models. Ponderomotive scaling of rescattering has enabled new avenues towards time-resolved probing of molecular structure. Essential for this paradigm shift was the convergence of two experimental tools: (1) intense mid-IR sources that can create high-energy photons and electrons while operating within the quasistatic regime and (2) detection systems that can detect the generated high-energy particles and image the entire momentum space of the interaction in full coincidence. Here, we present a unique combination of these two essential ingredients, namely, a 160-kHz mid-IR source and a reaction microscope detection system, to present an experimental methodology that provides an unprecedented three-dimensional view of strong-field interactions. The system is capable of generating and detecting electron energies that span a 6 order of magnitude dynamic range. We demonstrate the versatility of the system by investigating electron recollisions, the core process that drives strong-field phenomena, at both low (meV) and high (hundreds of eV) energies. The low-energy region is used to investigate recently discovered low-energy structures, while the high-energy electrons are used to probe atomic structure via laser-induced electron diffraction. Moreover, we present, for the first time, the correlated momentum distribution of electrons from nonsequential double ionization driven by mid-IR pulses.