中国物理B ›› 2019, Vol. 28 ›› Issue (11): 113301-113301.doi: 10.1088/1674-1056/ab4cdf

• ATOMIC AND MOLECULAR PHYSICS • 上一篇    下一篇

Field-free molecular orientation steered by combination of super-Gaussian and THz half-cycle laser pulses

Qi-Yuan Cheng(程起元), Yu-Zhi Song(宋玉志), Qing-Tian Meng(孟庆田)   

  1. 1 Medical Engineering Department, Shandong Provincial Hospital Affiliated to Shandong University, Jinan 250021, China;
    2 School of Physics and Electronics, Shandong Normal University, Jinan 250358, China
  • 收稿日期:2019-08-17 修回日期:2019-10-06 出版日期:2019-11-05 发布日期:2019-11-05
  • 通讯作者: Qing-Tian Meng E-mail:qtmeng@sdnu.edu.cn
  • 基金资助:
    Project supported by the National Natural Science Foundation of China (Grant Nos. 11674198 and 11874241) and the Taishan Scholar Project of Shandong Province, China.

Field-free molecular orientation steered by combination of super-Gaussian and THz half-cycle laser pulses

Qi-Yuan Cheng(程起元)1,2, Yu-Zhi Song(宋玉志)2, Qing-Tian Meng(孟庆田)2   

  1. 1 Medical Engineering Department, Shandong Provincial Hospital Affiliated to Shandong University, Jinan 250021, China;
    2 School of Physics and Electronics, Shandong Normal University, Jinan 250358, China
  • Received:2019-08-17 Revised:2019-10-06 Online:2019-11-05 Published:2019-11-05
  • Contact: Qing-Tian Meng E-mail:qtmeng@sdnu.edu.cn
  • Supported by:
    Project supported by the National Natural Science Foundation of China (Grant Nos. 11674198 and 11874241) and the Taishan Scholar Project of Shandong Province, China.

摘要: The molecular orientation created by laser fields is important for steering chemical reactions. In this paper, we propose a theoretical scheme to manipulate field-free molecular orientation by using an intense super-Gaussian laser pulse and a time-delayed terahertz half-cycle pulse (THz HCP). It is shown that the degree of field-free orientation can be doubled by the combined pulse with respect to the super-Gaussian pulse or THz HCP alone. Moreover, different laser intensities, carrier envelop phases, shape parameters, and time delays have great influence on the positive and negative orientations, with other conditions unchanged. Furthermore, it is indicated that the maximum degree and direction of molecular orientation can be precisely controlled by half of the duration of the super-Gaussian pulse. Finally, by adjusting the laser parameters of the super-Gaussian laser pulse and THz HCP, the optimal results of negative orientation and corresponding rotational populations are obtained at different temperatures of the molecular system.

关键词: molecular orientation, terahertz half-cycle pulse, super-Gaussian pulse

Abstract: The molecular orientation created by laser fields is important for steering chemical reactions. In this paper, we propose a theoretical scheme to manipulate field-free molecular orientation by using an intense super-Gaussian laser pulse and a time-delayed terahertz half-cycle pulse (THz HCP). It is shown that the degree of field-free orientation can be doubled by the combined pulse with respect to the super-Gaussian pulse or THz HCP alone. Moreover, different laser intensities, carrier envelop phases, shape parameters, and time delays have great influence on the positive and negative orientations, with other conditions unchanged. Furthermore, it is indicated that the maximum degree and direction of molecular orientation can be precisely controlled by half of the duration of the super-Gaussian pulse. Finally, by adjusting the laser parameters of the super-Gaussian laser pulse and THz HCP, the optimal results of negative orientation and corresponding rotational populations are obtained at different temperatures of the molecular system.

Key words: molecular orientation, terahertz half-cycle pulse, super-Gaussian pulse

中图分类号:  (Photon interactions with molecules)

  • 33.80.-b
33.15.Vb (Correlation times in molecular dynamics) 33.15.Kr (Electric and magnetic moments (and derivatives), polarizability, and magnetic susceptibility)