中国物理B ›› 2009, Vol. 18 ›› Issue (2): 571-580.doi: 10.1088/1674-1056/18/2/031

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Propagation of the off-axis superposition of partially coherent beams through atmospheric turbulence

季小玲1, 吕百达2, 张恩涛3   

  1. (1)College of Electronic Engineering, Sichuan Normal University, Chengdu 610066, China; (2)Institute of Laser Physics and Chemistry, Sichuan University, Chengdu 610064, China; (3)Institute of Laser Physics and Chemistry, Sichuan University, Chengdu 610064, China;School of Sciences of Southwest Petroleum University, Chengdu 610500, China
  • 收稿日期:2007-11-14 修回日期:2008-06-30 出版日期:2009-02-20 发布日期:2009-02-20
  • 基金资助:
    Project supported by the National Natural Science Foundation of China (Grant No 60778048).

Propagation of the off-axis superposition of partially coherent beams through atmospheric turbulence

Zhang En-Tao(张恩涛)a)b), Ji Xiao-Ling(季小玲)c), and Lü Bai-Da(吕百达)a)   

  1. a Institute of Laser Physics and Chemistry, Sichuan University, Chengdu 610064, China; b School of Sciences of Southwest Petroleum University, Chengdu 610500, China; c College of Electronic Engineering, Sichuan Normal University, Chengdu 610066, China 
  • Received:2007-11-14 Revised:2008-06-30 Online:2009-02-20 Published:2009-02-20
  • Supported by:
    Project supported by the National Natural Science Foundation of China (Grant No 60778048).

摘要: The propagation properties of the off-axis superposition of partially coherent beams through atmospheric turbulence and their beam quality in terms of the mean-squared beam width w(z) and the power in the bucket (PIB) are studied in detail, where the effects of partial coherence, off-axis beam superposition and atmospheric turbulence are considered. The analytical expressions for the intensity, the beam width and the PIB are derived, and illustrative examples are given numerically. It is shown that the maximum intensity Imax and the PIB decrease and w(z) increases as the refraction index structure constant Cn2 increases. Therefore, the turbulence results in a degradation of the beam quality. However, the resulting partially coherent beam with a smaller value of spatial correlation parameter γ and larger values of separate distance xd and beam number M is less affected by the turbulence than that with a larger value of γ and smaller values of xd and M. The main results obtained in this paper are explained physically.

关键词: off-axis superposition of partially coherent beams, atmospheric turbulence, propagation property, beam quality

Abstract: The propagation properties of the off-axis superposition of partially coherent beams through atmospheric turbulence and their beam quality in terms of the mean-squared beam width $w(z)$ and the power in the bucket (PIB) are studied in detail, where the effects of partial coherence, off-axis beam superposition and atmospheric turbulence are considered. The analytical expressions for the intensity, the beam width and the PIB are derived, and illustrative examples are given numerically. It is shown that the maximum intensity Imax and the PIB decrease and $w(z)$ increases as the refraction index structure constant Cn2 increases. Therefore, the turbulence results in a degradation of the beam quality. However, the resulting partially coherent beam with a smaller value of spatial correlation parameter $\gamma$ and larger values of separate distance xd and beam number M is less affected by the turbulence than that with a larger value of $\gamma$ and smaller values of xd and M. The main results obtained in this paper are explained physically.

Key words: off-axis superposition of partially coherent beams, atmospheric turbulence, propagation property, beam quality

中图分类号:  (Convection, turbulence, and diffusion)

  • 92.60.hk
42.68.Bz (Atmospheric turbulence effects) 42.25.Bs (Wave propagation, transmission and absorption) 42.25.Kb (Coherence)