Enhancement of strong-field ionization in two-color circularly polarized laser fields via photon-spin control
Enhancement of strong-field ionization in two-color circularly polarized laser fields via photon-spin control
复制标题
通过光子自旋控制增强双色圆偏振激光场中的强场电离
DOI：
10.1103/physreva.95.012501
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发表时间：
2017
影响因子：
2.9
通讯作者：
and M. M. Murnane
中科院分区：
文献类型：
--
作者：
C. A. Mancuso;K. M. Dorney;D. D. Hickstein;J. L. Chaloupka;X. M. Tong;J. L. Ellis; H. C. Kapteyn;and M. M. Murnane
利用超短飞秒真空紫外（VUV）和红外（IR）脉冲，采用抽运-探测的方法，研究了中性分子激发态的动力学和非平衡解离通道。在中性分子状态下，通过吸收驱动红外激光场的九次谐波，产生一个核子波包。由于在电子态激发的分子具有很大的伸缩振幅，在束缚态、高电子态和振动激发态的势能曲线上，有效电离势随着原子核波包的振动而发生显著的变化。我们探测这样的动力学电离的激发中性分子使用时间延迟的VUV或IR辐射。我们确定了非平衡解离通道，利用三维动量成像的离子碎片。我们发现，不同的解离通道可以控制，在一定程度上，通过改变红外激光强度和通过选择的探测激光的波长。此外，我们的结论是，即使在一个基准的分子系统，如 *，非平衡多光子和双光子电离过程的解释仍然是一个具有挑战性的任务，需要复杂的理论分析。
We used ultrashort femtosecond vacuum ultraviolet (VUV) and infrared (IR) pulses in a pump-probe scheme to map the dynamics and nonequilibrium dissociation channels of excited neutralmolecules. A nuclear wave packet is created in thestate of the neutralmolecule by absorption of the ninth harmonic of the driving infrared laser field. Due to the large stretching amplitude of the molecule excited in theelectronic state, the effectiveionization potential changes significantly as the nuclear wave packet vibrates in the bound, highly electronically and vibrationally excitedpotential-energy curve. We probed such dynamics by ionizing the excited neutral molecule using time-delayed VUV-or-IR radiation. We identified the nonequilibrium dissociation channels by utilizing three-dimensional momentum imaging of the ion fragments. We found that different dissociation channels can be controlled, to some extent, by changing the IR laser intensity and by choosing the wavelength of the probe laser light. Furthermore, we concluded that even in a benchmark molecular system such as*, the interpretation of the nonequilibrium multiphoton and multicolor ionization processes is still a challenging task, requiring intricate theoretical analysis.