静电场对强激光场非序列双电子电离的影响

The effect of static electric field on nonsequential double ionization

利用半经典重碰模型计算并研究了He原子在强激光场与静电场的混合场下的非序列双电子电离过程.由于静电场破坏了激光场电场的反演对称性,在平行于激光场偏振方向的He2+离子动量分布不再具有对称双峰结构.由于超短脉冲具有相似的非对称性,研究静电场对原子在强场中非序列电离的影响,有助于分析超短脉冲非序列电离的过程,进一步了解非序列双电子电离的机理.

Nonsequential double ionization of He atom in the combined field of a laser and a static electric field has been investigated. It is found that the presence of the static electric field breaks the inversion and reflection symmetry, the symmetric double-peak structure of the He^2＋ ion momentum parallel to the polarization of the laser field is broken. Since the ultrashort laser pulse has the similar asymmetric character, this study is helpful to understand the mechanism of the double ionization process in ultrashort laser field.