Shaper-based photoelectron tomography of free electron wave packets from multiphoton ionization with tailored 3D laser fields

在这个提议中，我们提出了一种实验方法来产生完全可控和定制的三维（3D）超短激光光场。三维场是在以不同角度向不同方向传播的两束偏振型飞秒激光束的焦点上产生的。在最近的理论研究中，这些所谓的“超手性”光场被证明为区分对映体提供了异常高的灵敏度。我们项目的主要目标是通过实验探索定制的3D光场提供的新的可能性，用于原子和分子光电离动力学的相干控制。在实验中，我们通过测量释放的自由电子波包的三维光电子动量分布（PMD）来研究原子和手性分子在这些完全受控的三维激光场下的多光子电离（MPI）。由于现有的基于波片的光电子层析成像技术不适用于三维场，我们引入了一种新的基于脉冲整形器的光电子层析成像方法来精确测量和重建全三维PMDs。在我们的实验中，MPI作为一个模型系统来分析三维场驱动的超快动力学相干控制的物理机制。同时，该方法是一种非常灵敏的非线性方法，可用于三维场的原位表征。我们通过讨论各种MPI场景并展示仅由这些3D字段访问的相应模拟3D pmd来展示我们方法的新颖性。通过与已有实验结果的对比，验证了仿真方法的有效性。在提议的项目中，我们结合了我们在先进的超连续介质极化脉冲整形，高精度光电子断层扫描以及原子和分子动力学相干控制理论建模方面的专业知识。我们的中心目标是实验生成和控制前所未有的3D pmd使用3D领域。量身定制的3D领域为光诱导超快过程的控制开辟了新的前景，不仅在相干控制方面，而且在原子，分子和光学物理的许多领域，如手性识别，激光光谱学，非线性显微镜，激光化学，量子信息和材料加工等。

In this proposal, we suggest an experimental method for generating fully controlled and tailored three-dimensional (3D) ultrashort laser light fields. The 3D field is created in the focus of two polarization-shaped femtosecond laser beams propagating at an angle in different directions. In recent theoretical studies, these so-called “super-chiral” light fields have been shown provide exceptionally high sensitivity for distinguishing enantiomers. The main goal of our project is to experimentally explore the new possibilities offered by tailored 3D light fields for coherent control of atomic and molecular photoionization dynamics. In the proposed experiment, we investigate the multiphoton ionization (MPI) of atoms and chiral molecules with these fully controlled 3D laser fields by measuring the 3D photoelectron momentum distributions (PMD) of the released free electron wave packets. Because our established waveplate-based photoelectron tomography technique is not applicable to 3D fields, we introduce a novel pulse shaper-based photoelectron tomography method to accurately measure and reconstruct the full 3D PMDs. In our experiments, MPI serves as a model system to analyze the physical mechanisms of coherent control of ultrafast dynamics driven by 3D fields. At the same time, this method is used as a very sensitive nonlinear method for in-situ characterization of these 3D fields. We demonstrate the novelty of our approach by discussing various MPI scenarios and showing the corresponding simulated 3D PMDs which are only accessible by these 3D fields. We validate the simulation method by comparison with our previous experimental results.In the proposed project, we combine our expertise in advanced supercontinuum polarization pulse shaping, high-precision photoelectron tomography, and theoretical modeling of coherent control of atomic and molecular dynamics. Our central goal is the experimental generation and control of unprecedented 3D PMDs using 3D fields. Tailored 3D fields open new prospects for the control of light-induced ultrafast processes, not only in coherent control, but also in many areas of atomic, molecular, and optical physics such as chiral recognition, laser spectroscopy, nonlinear microscopy, laser chemistry, quantum information, and materials processing, to name a few.