中国物理B ›› 2018, Vol. 27 ›› Issue (5): 53701-053701.doi: 10.1088/1674-1056/27/5/053701

• ATOMIC AND MOLECULAR PHYSICS • 上一篇    下一篇

Optical Stark deceleration of neutral molecules from supersonic expansion with a rotating laser beam

Yongcheng Yang(杨永成), Shunyong Hou(侯顺永), Lianzhong Deng(邓联忠)   

  1. State Key Laboratory of Precision Spectroscopy, East China Normal University, Shanghai 200062, China
  • 收稿日期:2018-01-06 修回日期:2018-02-01 出版日期:2018-05-05 发布日期:2018-05-05
  • 通讯作者: Lianzhong Deng E-mail:lzdeng@phy.ecnu.edu.cn
  • 基金资助:
    Project supported by the National Natural Science Foundation of China (Grant Nos.11504112,91536218,and 11604100).

Optical Stark deceleration of neutral molecules from supersonic expansion with a rotating laser beam

Yongcheng Yang(杨永成), Shunyong Hou(侯顺永), Lianzhong Deng(邓联忠)   

  1. State Key Laboratory of Precision Spectroscopy, East China Normal University, Shanghai 200062, China
  • Received:2018-01-06 Revised:2018-02-01 Online:2018-05-05 Published:2018-05-05
  • Contact: Lianzhong Deng E-mail:lzdeng@phy.ecnu.edu.cn
  • Supported by:
    Project supported by the National Natural Science Foundation of China (Grant Nos.11504112,91536218,and 11604100).

摘要: Cold molecules have great scientific significance in high-resolution spectroscopy, precision measurement of physical constants, cold collision, and cold chemistry. Supersonic expansion is a conventional and versatile method to produce cold molecules with high kinetic energies. We theoretically show here that fast-moving molecules from supersonic expansion can be effectively decelerated to any desired velocity with a rotating laser beam. The orbiting focus spot of the red-detuned laser serves as a two-dimensional potential well for the molecules. We analyze the dynamics of the molecules inside the decelerating potential well and investigate the dependence of their phase acceptance by the potential well on the tilting angle of the laser beam. ND3 molecules are used in the test of the scheme and their trajectories under the impact of the decelerating potential well are numerically simulated using the Monte Carlo method. For instance, with a laser beam of 20 kW in power focused into a pot of 40 μ in waist radius, ND3 molecules of 250 m/s can be brought to a standstill by the decelerating potential well within a time interval of about 0.73 ms. The total angle covered by the rotating laser beam is about 5.24° with the distance travelled by the potential well being about 9.13 cm. In fact, the molecules can be decelerated to any desired velocity depending on the parameters adopted. This scheme is simple in structure and easy to be realized in experiment. In addition, it is applicable to decelerating both molecules and atoms.

关键词: cold molecules, optical potential, Stark deceleration

Abstract: Cold molecules have great scientific significance in high-resolution spectroscopy, precision measurement of physical constants, cold collision, and cold chemistry. Supersonic expansion is a conventional and versatile method to produce cold molecules with high kinetic energies. We theoretically show here that fast-moving molecules from supersonic expansion can be effectively decelerated to any desired velocity with a rotating laser beam. The orbiting focus spot of the red-detuned laser serves as a two-dimensional potential well for the molecules. We analyze the dynamics of the molecules inside the decelerating potential well and investigate the dependence of their phase acceptance by the potential well on the tilting angle of the laser beam. ND3 molecules are used in the test of the scheme and their trajectories under the impact of the decelerating potential well are numerically simulated using the Monte Carlo method. For instance, with a laser beam of 20 kW in power focused into a pot of 40 μ in waist radius, ND3 molecules of 250 m/s can be brought to a standstill by the decelerating potential well within a time interval of about 0.73 ms. The total angle covered by the rotating laser beam is about 5.24° with the distance travelled by the potential well being about 9.13 cm. In fact, the molecules can be decelerated to any desired velocity depending on the parameters adopted. This scheme is simple in structure and easy to be realized in experiment. In addition, it is applicable to decelerating both molecules and atoms.

Key words: cold molecules, optical potential, Stark deceleration

中图分类号:  (Slowing and cooling of molecules)

  • 37.10.Mn
37.10.Pq (Trapping of molecules) 32.60.+i (Zeeman and Stark effects)