Laser phase effect on asymmetric harmonic distribution in H2

• 来源期刊: 中国物理B（英文版）
• 关键词: molecular high-order harmonic generation spatial distribution of molecular harmonics laser phase effect isotope effect
• 年，卷（期）: 2017,（4）
• 页码范围: 219-224
• 页数: 6页
• 语种: 英文
• DOI: 10.1088/1674-1056/26/4/044206

摘要

The laser phase effect on the spatial distribution of the molecular high-order harmonic generation (MHHG) spectrum from H2+ is theoretically investigated through solving the Non-Bohn-Oppenheimer (NBO) time-dependent Schr(o)dinger equation (TDSE).The results are shown as follows.(i) The generated harmonics from the two nuclei each present an asymmetric distribution.Particularly,when the laser phases are chosen from 0.0π to 0.6π and from 1.7π to 2.0π,the contribution from the negative-H plays a main role in harmonic generation.When the laser phases are chosen from 0.7π to 1.6π,the contribution from the positive-H to the harmonic generation is remarkably enhanced and becomes greater than that from the negative-H.The electron localization,the time-frequency analyses of the harmonic spectrum and the time-dependent wave function are shown to explain the asymmetric harmonic distribution in H2+,which provides us with a method to control the electron motion in molecules.(ii) As the pulse duration increases,the asymmetric distributions of the MHHG in two H nuclei decrease.(iii) Isotope investigation shows that the asymmetric harmonic distribution can be reduced by introducing the heavy nucleus (i.e.,D2+).