物理学报2017，Vol.66Issue(12)：173-180,8.DOI:10.7498/aps.66.124205
随机电磁高阶Bessel-Gaussian光束在海洋湍流中的传输特性
Propagation of stochastic electromagnetic high-order Bessel-Gaussian beams in the oceanic turbulence
摘要
Abstract
Recently, the laser beam propagation in the oceanic turbulence has become a hot research topic. In addition to the characteristics of free diffraction and self-reconstruction, the high-order Bessel-Gaussian beam is a kind of typical vortex beam because of the existence of a spiral phase factor with orbital angular momentum. Researchers have investigated the self-reconstruction property of the high-order Bessel-Gaussian beams in the free space, also carried out intensive researches on the transmission characteristics of high-order Bessel-Gaussian beam in the ABCD optical system and in the atmospheric turbulence. However, to the best of our knowledge, to date there has been no investigation on the propagation of this laser beam in the oceanic turbulence. In this paper, we will study the propagation characteristics of the random electromagnetic high-order Bessel-Gaussian beams in the oceanic turbulence, and discuss the variation of the normalized spectrum intensity, the spectral degree of polarization, and the spectral degree of coherence. By using the extended Huygens-Fresnel diffraction integral formula, the general expression for the cross spectral density matrix of the stochastic electromagnetic high-order Bessel-Gaussian beams propagating in the oceanic turbulence is obtained, and the statistical properties of the random electromagnetic high-order Bessel-Gaussian beams propagating in the seawater are investigated by numerical calculation. The numerical results show that the oceanic turbulence can affect the normalized spectral intensity distribution of the random electromagnetic beam. With the increase of the transmission distance, the center of the zero-order Bessel-Gaussian beam becomes depressed, and the center of the higher-order Bessel-Gaussian beam will become flat and then depressed. As the transmission distance increases far enough, regardless of the zero-order or higher-order, the intensity distribution will eventually evolve into the quasi Gaussian shaped distribution. The variation of the degree of polarization of each point on the x axis is related to the coherence length (δxx, δyy) and the oceanic turbulence parameters. The spectral coherence of the origin and any point on the x axis also changes with the increase of x, and the rate of dissipation of mean-square temperature χT has influence on the spectral coherence. This research is of great value for applying the high-order Bessel-Gaussian beam to the optical communication, optical imaging and underwater exploration in the ocean.关键词
海洋湍流/随机电磁光束/高阶Bessel-Gaussian光束/传输Key words
oceanic turbulence/stochastic electromagnetic beam/high order Bessel-Gaussian beam/propagation引用本文复制引用
刘永欣,陈子阳,蒲继雄..随机电磁高阶Bessel-Gaussian光束在海洋湍流中的传输特性[J].物理学报,2017,66(12):173-180,8.基金项目
国家自然科学基金(批准号:61505059, 61575070, 11504116)、福建省教育厅科技项目(批准号:JA15038)和华侨大学高层次人才启动经费(批准号:12BS231 资助的课题. Project supported by the National Natural Science Foundation of China(Grant Nos. 61505059, 61575070, 11504116), the Project of Education Department of Fujian Province, China(Grant No. JA15038), and the High level talent research of Huaqiao University, China(Grant No. 12BS231. （批准号:61505059, 61575070, 11504116）
