中国物理B ›› 2014, Vol. 23 ›› Issue (12): 124213-124213.doi: 10.1088/1674-1056/23/12/124213

• ELECTROMAGNETISM, OPTICS, ACOUSTICS, HEAT TRANSFER, CLASSICAL MECHANICS, AND FLUID DYNAMICS • 上一篇    下一篇

Calculation and analysis of the number of return photons from sodium laser beacon excited by the long pulse laser with circular polarization

刘向远a b, 钱仙妹a, 李玉杰a, 饶瑞中a   

  1. a Key Laboratory of Atmospheric Composition and Optical Radiation, Anhui Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Hefei 230031, China;
    b College of Materials and Chemical Engineering, West Anhui University, Lu'an 237012, China
  • 收稿日期:2014-04-15 修回日期:2014-06-17 出版日期:2014-12-15 发布日期:2014-12-15
  • 基金资助:

    Project supported by the National Natural Science Foundation of China (Grant No. 61107066) and the College Natural Science Foundation of Anhui Province, China (Grant No. KJ2013B331).

Calculation and analysis of the number of return photons from sodium laser beacon excited by the long pulse laser with circular polarization

Liu Xiang-Yuan (刘向远)a b, Qian Xian-Mei (钱仙妹)a, Li Yu-Jie (李玉杰)a, Rao Rui-Zhong (饶瑞中)a   

  1. a Key Laboratory of Atmospheric Composition and Optical Radiation, Anhui Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Hefei 230031, China;
    b College of Materials and Chemical Engineering, West Anhui University, Lu'an 237012, China
  • Received:2014-04-15 Revised:2014-06-17 Online:2014-12-15 Published:2014-12-15
  • Contact: Liu Xiang-Yuan, Qian Xian-Mei E-mail:lxy0564@aliyun.com;qianxianmei@aiofm.ac.cn
  • Supported by:

    Project supported by the National Natural Science Foundation of China (Grant No. 61107066) and the College Natural Science Foundation of Anhui Province, China (Grant No. KJ2013B331).

摘要:

The number of return photons from sodium laser beacon (SLB) greatly suffers down-pumping, recoil, and geomagnetic field when the long pulse laser with circular polarization interacts with sodium atoms in the mesosphere. Considering recoil and down-pumping effects on the number of return photons from SLB, the spontaneous radiation rates are obtained by numerical computations and fittings. Furthermore, combining with the geomagnetic field effects, a new expression is achieved for calculating the number of return photons. By using this expression and considering the stochastic distribution of laser intensity in the mesosphere under different turbulence models for atmosphere, the number of return photons excited by the narrow-band single mode laser and that by the narrow-band three-mode laser are respectively calculated. The results show that the narrow-band three-mode laser with a specific spectrum structure has a higher spontaneous radiation rate and more return photons than a narrow-band single mode laser. Of note, the effect of the atmospheric turbulence on the number of return photons is remarkable. Calculation results indicate that the number of return photons under the HV5/7 model for atmospheric turbulence is much higher than that under the Greenwood and ModHV models.

关键词: sodium laser beacon, spontaneous radiation rates, the number of return photons, down-pumping, recoil, geomagnetic field

Abstract:

The number of return photons from sodium laser beacon (SLB) greatly suffers down-pumping, recoil, and geomagnetic field when the long pulse laser with circular polarization interacts with sodium atoms in the mesosphere. Considering recoil and down-pumping effects on the number of return photons from SLB, the spontaneous radiation rates are obtained by numerical computations and fittings. Furthermore, combining with the geomagnetic field effects, a new expression is achieved for calculating the number of return photons. By using this expression and considering the stochastic distribution of laser intensity in the mesosphere under different turbulence models for atmosphere, the number of return photons excited by the narrow-band single mode laser and that by the narrow-band three-mode laser are respectively calculated. The results show that the narrow-band three-mode laser with a specific spectrum structure has a higher spontaneous radiation rate and more return photons than a narrow-band single mode laser. Of note, the effect of the atmospheric turbulence on the number of return photons is remarkable. Calculation results indicate that the number of return photons under the HV5/7 model for atmospheric turbulence is much higher than that under the Greenwood and ModHV models.

Key words: sodium laser beacon, spontaneous radiation rates, the number of return photons, down-pumping, recoil, geomagnetic field

中图分类号:  (Atmospheric and ocean optics)

  • 42.68.-w
42.68.Bz (Atmospheric turbulence effects) 42.68.Mj (Scattering, polarization) 42.62.-b (Laser applications)