中国物理B ›› 2005, Vol. 14 ›› Issue (10): 1960-1965.doi: 10.1088/1009-1963/14/10/008

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The multielectron dissociative ionization dynamics of N2 molecule in intense femtosecond laser fields with arbitrary polarization

陈建新, 龚旗煌   

  1. State Key Laboratory for Mesoscopic Physics, Department of Physics,Peking University, Beijing 100871, China
  • 收稿日期:2004-10-10 修回日期:2005-05-23 出版日期:2005-10-20 发布日期:2005-10-20
  • 基金资助:
    roject supported by the National Key Basic Research Special Foundation (NKBRSF) (Grant No TG1999075207) and the National Natural Science Foundation of China (Grant Nos 10104003,90206003 and 60378012) and the China Postdoctoral Science Foundation (Grant No

The multielectron dissociative ionization dynamics of N2 molecule in intense femtosecond laser fields with arbitrary polarization

Chen Jian-Xin (陈建新), Gong Qi-Huang (龚旗煌)   

  1. State Key Laboratory for Mesoscopic Physics, Department of Physics,Peking University, Beijing 100871, China
  • Received:2004-10-10 Revised:2005-05-23 Online:2005-10-20 Published:2005-10-20
  • Supported by:
    roject supported by the National Key Basic Research Special Foundation (NKBRSF) (Grant No TG1999075207) and the National Natural Science Foundation of China (Grant Nos 10104003,90206003 and 60378012) and the China Postdoctoral Science Foundation (Grant No

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摘要： The field-ionization Coulomb explosion model is extended to investigate the multielectron dissociative ionization process of N2 molecule irradiated by an intense femtosecond laser field with an arbitrary polarization. The ionization process of N2 molecule is found to be optimal at the critical internuclear distance Rc=7a.u., which is independent of the laser polarization state, the molecular explosion channel and the angle between the molecular axis and the direction of laser electric field. The kinetic energies of the ion fragments are identical in the cases of linear and circular polarizations at the same incident laser intensity. However,the probability of electron ionization is very sensitive to the above three parameters. At the critical distance Rc=7a.u. the angular dependence of the threshold intensity for the over-the-barrier ionization leads to the geometric alignment of molecules in the case of linear polarization. The threshold intensity in the case of circular polarization is apparently higher than that in the case of linear polarization, which can well explain the significant decrease of ionization in the case of circular polarization. The numerical calculations are compared with the experimental measurements.

关键词: multielectron dissociative ionization, arbitrary femtosecond laser polarization, N2

Abstract: The field-ionization Coulomb explosion model is extended to investigate the multielectron dissociative ionization process of N2 molecule irradiated by an intense femtosecond laser field with an arbitrary polarization. The ionization process of N2 molecule is found to be optimal at the critical internuclear distance Rc=7a.u., which is independent of the laser polarization state, the molecular explosion channel and the angle between the molecular axis and the direction of laser electric field. The kinetic energies of the ion fragments are identical in the cases of linear and circular polarizations at the same incident laser intensity. However,the probability of electron ionization is very sensitive to the above three parameters. At the critical distance Rc=7a.u. the angular dependence of the threshold intensity for the over-the-barrier ionization leads to the geometric alignment of molecules in the case of linear polarization. The threshold intensity in the case of circular polarization is apparently higher than that in the case of linear polarization, which can well explain the significant decrease of ionization in the case of circular polarization. The numerical calculations are compared with the experimental measurements.

Key words: multielectron dissociative ionization, arbitrary femtosecond laser polarization, N2

中图分类号:  (Diffuse spectra; predissociation, photodissociation)

  • 33.80.Gj
33.80.Eh (Autoionization, photoionization, and photodetachment) 34.80.Gs (Molecular excitation and ionization) 34.80.Ht (Dissociation and dissociative attachment)