Mancuso Christopher A, Dorney Kevin M, Hickstein Daniel D, Chaloupka Jan L, Ellis Jennifer L, Dollar Franklin J, Knut Ronny, Grychtol Patrik, Zusin Dmitriy, Gentry Christian, Gopalakrishnan Maithreyi, Kapteyn Henry C, Murnane Margaret M
JILA, Department of Physics, University of Colorado and NIST, Boulder, Colorado 80309, USA.
Department of Physics and Astronomy, University of Northern Colorado, Greeley, Colorado 80639, USA.
Phys Rev Lett. 2016 Sep 23;117(13):133201. doi: 10.1103/PhysRevLett.117.133201. Epub 2016 Sep 20.
Atoms undergoing strong-field ionization in two-color circularly polarized femtosecond laser fields exhibit unique two-dimensional photoelectron trajectories and can emit bright circularly polarized extreme ultraviolet and soft-x-ray beams. In this Letter, we present the first experimental observation of nonsequential double ionization in these tailored laser fields. Moreover, we can enhance or suppress nonsequential double ionization by changing the intensity ratio and helicity of the two driving laser fields to maximize or minimize high-energy electron-ion rescattering. Our experimental results are explained through classical simulations, which also provide insight into how to optimize the generation of circularly polarized high harmonic beams.
原子在双色圆偏振飞秒激光场中经历强场电离时，会展现出独特的二维光电子轨迹，并能发射明亮的圆偏振极紫外和软X射线光束。在本信函中，我们展示了在这些定制激光场中非顺序双电离的首次实验观测结果。此外，我们可以通过改变两个驱动激光场的强度比和螺旋度来增强或抑制非顺序双电离，以最大化或最小化高能电子 - 离子再散射。我们的实验结果通过经典模拟得到了解释，这些模拟还为如何优化圆偏振高次谐波光束的产生提供了见解。
