论文标题
通过三型多通道波数据包干涉测定原子多光子电离阶段
Determination of atomic multiphoton ionization phases by trichromatic multichannel wave packet interferometry
论文作者
论文摘要
我们提出了一种基于三色脉冲成型的多通道光电子干涉测定法，以明确测定钾原子多光子离子化（MPI）中的量子相。选择激光场的颜色以在连续体中产生三个能量分离的光电子干涉图。虽然红色脉冲是两光脉冲谐振剂，并带有$ 3D $状态，从而导致了（2+1）共振增强的MPI（REMPI），但A（1+2）REMPI通过非谐振的中间体$ 4P $ -STATE发生，具有初始绿色或蓝色的脉冲。我们表明，通过非谐振中间状态的电离将光电干涉图的退化从由颜色的排列组成的途径中解脱出来。对干涉图的分析揭示了$ \pmπ/2 $的相移，具体取决于（1+2）REMPI途径中的引导符号。此外，我们证明了共振（2+1）REMPI途径的光离子延迟导致光电光谱中的线性光谱相。通过分析性扰动描述和三色驱动的三级系统耦合到连续体的分析性扰动描述和数值模拟，获得了对基础MPI过程的见解。
We present a multichannel photoelectron interferometry technique based on trichromatic pulse shaping for unambiguous determination of quantum phases in multiphoton ionization (MPI) of potassium atoms. The colors of the laser field are chosen to produce three energetically separated photoelectron interferograms in the continuum. While the red pulse is two-photon resonant with the $3d$-state resulting in a (2+1) resonance-enhanced MPI (REMPI), a (1+2) REMPI occurs via the non-resonant intermediate $4p$-state with an initial green or blue pulse. We show that ionization via a non-resonant intermediate state lifts the degeneracy of photoelectron interferograms from pathways consisting of permutations of the colors. The analysis of the interferograms reveals a phase shift of $\pm π/2$ depending on the sign of the detunings in the (1+2) REMPI pathways. In addition, we demonstrate that the photoionization time delay in the resonant (2+1) REMPI pathway gives rise to a linear spectral phase in the photoelectron spectra. Insights into the underlying MPI processes are gained through an analytic perturbative description and numerical simulations of a trichromatic driven three level system coupled to the continuum.
