Elliptic dichroism in strong-field ionization of atoms subjected to tailored laser fields
Elliptic dichroism in strong-field ionization of atoms subjected to tailored laser fields
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DOI：
10.1039/d1cp05209h
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发表时间：
2022-02-25
影响因子：
3.3
通讯作者：
Milosevic, Dejan B.
中科院分区：
文献类型：
--
作者：
Becker, Wilhelm;Milosevic, Dejan B.
在磁量子数上平均的原子系统的定制激光场对强场电离的微分电离率满足特定的反转和反射对称性。详细讨论了与激光场椭圆度符号变化有关的椭圆二向色性参数的对称性，特别强调了高阶高于阈值的电离。以椭圆偏振激光场和双椭圆正交偏振双色(BEOTC)场为例说明了一般结果。对于BEOTC场，研究了欧米伽-2欧米伽和欧米伽-3欧米伽场组合的微分电离率和椭圆二向色性参数，以及激光场分量之间的不同相对位相。光电子动量分布在场极化面上的反转和反射对称性取决于r和S在零场-S欧米伽BEOTC场组合中的奇偶数以及场分量之间的相对相位。我们认为，通过分析椭圆二向色性参数测量动量分布的对称性，可以确定强场电离的机制。如果再散射机制占主导地位，人们可以利用这些分布来获得关于原子和分子结构和动力学的信息。
The differential ionization rate for strong-field ionization by tailored laser fields of atomic systems averaged over the magnetic quantum number satisfies particular inversion and reflection symmetries. The symmetries of the elliptic-dichroism parameter, which is related to the change of sign of the ellipticity of the laser field, are considered in detail, with particular emphasis on high-order above-threshold ionization. The general results are illustrated by the examples of an elliptically polarized laser field and a bi-elliptical orthogonally polarized two-color (BEOTC) field. For the BEOTC field the differential ionization rate and the elliptic-dichroism parameter are investigated for the omega-2 omega and omega-3 omega field combinations and for various relative phases between the laser-field components. The inversion and reflection symmetries of the photoelectron momentum distribution in the polarization plane of the field depend on the parities of r and s in the r omega--s omega BEOTC field combination and on the relative phase between the field components. We suggest that, by analyzing the symmetry properties of the measured momentum distribution of the elliptic-dichroism parameter, one can identify the mechanism of strong-field ionization. If the rescattering mechanism is dominant one can use these distributions to obtain information about the atomic and molecular structure and dynamics.