物理化学学报 >> 2004, Vol. 20 >> Issue (08S): 1055-1062.doi: 10.3866/PKU.WHXB200408zk24

综述 上一篇    

多原子分子在强飞秒激光场中的解离

王操;孔繁敖   

  1. 中国科学院化学研究所,分子反应动力学国家重点实验室,北京 100080
  • 收稿日期:2004-04-30 修回日期:2004-05-31 发布日期:2004-08-15
  • 通讯作者: 孔繁敖 E-mail:kong@iccas.ac.cn

Dissociation of Polyatomic Molecules in the Intense Femtosecond Laser Field

Wang Cao;Kong Fan-Ao   

  1. State Key Laboratory of Molecular Reaction Dynamics, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100080
  • Received:2004-04-30 Revised:2004-05-31 Published:2004-08-15
  • Contact: Kong Fan-Ao E-mail:kong@iccas.ac.cn

摘要: 强场化学是一个新的研究领域,分子在强激光场中解离则是该领域中的一个重要课题.本文阐述分子在强飞秒激光场(1013~1014 W•cm-2)中的解离规律以及我们所提出的场致解离(FAD)理论.在模型中我们考虑的是分子离子的解离,而且只考虑那些键轴平行于激光场方向的离子.此模型要求先计算出分子离子的缀饰势能面(Dressed PES),再计算键长随时间变化的准经典轨线(QCT).以甲烷、丙酮为例进行了实验和理论研究,理论计算的结果能很好地阐明观察到的实验结果.

关键词: 强飞秒激光场, 飞行时间质谱, 场致解离, 甲烷, 丙酮

Abstract: Chemistry in strong laser fields is a new research field in which dissociation of molecules in the intense laser field is a current topic of interest. Our results, including the theoretical model of field-assisted dissociation (FAD) and the experimental investigations on the dissociation of CH4 and CH3COCH3 in the intense femtosecond laser field are presented. Some assumptions are made in the model. When a laser field applies to a molecule, only the change of the one bond length, which lies along with the laser field, is taken into account and the rest of the molecular geometry is fixed. In addition, only molecular ions in the ground electronic state are considered. Ab initio potential energy surfaces in the external fields indicate that chemical bond tends to dissociate. QCT (quasi-classical trajectory) calculations clearly show the processes of bond breaking. It was found that the calculations based on the theoretical model are in excellent agreement with the experiment data.

Key words: Intense femtosecond laser field, TOF-MS, Field-assisted dissociation,  Methane, Acetone