Internuclear-distance dependence of ionization of H2 in strong laser fields
Internuclear-distance dependence of ionization of H2 in strong laser fields
复制标题
强激光场中 H2 电离的核间距离依赖性
DOI：
10.1088/0953-4075/39/13/s12
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发表时间：
2006
期刊：
影响因子：
--
通讯作者：
A. Saenz
中科院分区：
文献类型：
--
作者：
M. Awasthi;A. Saenz
研究了强激光脉冲作用下氢分子的电离产额与核间距R的关系。通过三维含时薛定谔方程（TDSE）描述电子运动的完全解决方案所获得的结果进行了比较与准静态近似（QSA）的预测。结果发现，对于波长为800 nm，峰值强度在3.5 × 1013 W cm−2和1 × 1014 W cm−2之间的激光脉冲，QSA预测的R依赖性与TDSE结果定性一致，只要在QSA模型中使用垂直电离势。然而，定量协议强烈依赖于激光强度。虽然800 nm的产额随R平滑变化，但266 nm（和3.5 × 1013 W cm−2）的情况并非如此。正如预期的那样，对于这些参数的电离动力学更好地描述为一个多光子过程，它是强烈的通道关闭和共振增强多光子电离的外观的影响。
The ionization yield of molecular hydrogen exposed to intense laser pulses is studied as a function of the internuclear distance R. The results obtained by means of the full solution of the three-dimensional time-dependent Schrödinger equation (TDSE) describing electronic motion are compared with those predicted by the quasi-static approximation (QSA). It is found that for laser pulses with a wavelength of 800 nm and peak intensities between 3.5 × 1013 W cm−2 and 1 × 1014 W cm−2 the QSA predicts an R dependence that is in qualitative agreement with the TDSE results, provided a vertical ionization potential is used in the QSA model. The quantitative agreement depends, however, strongly on the laser intensity. While the yields for 800 nm vary smoothly with R, this is not the case for 266 nm (and 3.5 × 1013 W cm−2). As expected, for these parameters the ionization dynamics is better described as a multi-photon process; it is strongly influenced by channel closing and the appearance of resonantly enhanced multi-photon ionization.