Studies On The Propagation Of The Specular And Anti-specular Gaussian Schell-model Beams Through Turbulent Mediums

Since the ruby laser was invented in 1960, laser has been widely applied in various fields because of the advantages in directionality, monochromaticity, coherence and brightness. Due to the requirements of practical applications such as optical communication and remote sensing, the transfer characteristics of many kinds of laser beams passing through a variety of optical systems and mediums have attracted lots of research attention all around the word. The concept of specular cross-spectral density function was firstly proposed by Gori et al. in 1988, however little attention has been paid to specularity in the following decades. Until recent years, the specularity was extended to two-dimension and anti-specularity was also proposed by Partanen et al. The specular light beams and anti-specular beams possess some peculiarities and have potential applications in certain fields, however, except for the utilization of particles trapping by Guo et al., the application in other fields has not been explored. In this context, we explored the transfer properties of specular Gaussian Schell-model light beams and anti-specular Gaussian Schell-model light beams propagating in free space, atmospheric turbulence and oceanic turbulence. Some meaningful conclusions were obtained.Our article consists of four parts, and showing as follows:In Chapter 1, there is an introduction. Firstly, the research background is introduced in three aspects:the application values of our research, some usual turbulent mediums and factors which influence those turbulences, the feature of specular beams and anti-specular beams. Then we introduced some fundamental theory which being important in our study:the cross-spectral density function, the extended Huygens-Fresnel principle, the transfer theory of light beams passing through turbulent medium, the non-kolmogorov atmospheric turbulence model, the oceanic turbulence model. Moreover, we introduced how to generate the specular and anti-specular light beams.In Chapter 2, the cross-spectral density function of anisotropic specular and anti-specular beams passing through non-Kolmogorov turbulent atmosphere was derived. Base on the expression, we explored the evolutionary behavior of optical statistical properties on propagation. We found the turbulent atmosphere have a obvious influence on the spectral density of the anti-specular beams on propagation and would destroy the specularity of specular beams or the anti-specularity of anti-specular beams, moreover, the spectral degree of coherence of anti-specular beams have a different distribution with the specular beams when propagating in atmospheric turbulence.In Chapter 3, we derived the cross spectral density function of the isotropic specular and anti-specular beams propagating in oceanic turbulence. Then we mainly studied the influence of the strength of oceanic turbulence and the property of light beams on the optical statistical properties of the specular and anti-specular beams on propagation. The simulation result revealed that, when propagating in oceanic turbulence, the optical statistical properties perform similar evolutionary behavior as propagating in atmospheric turbulence, stronger turbulence would enhance the evolutionary process and cause a wider beam width at identical propagation distance, what is more, beams with poorer coherence is more vulnerable to turbulence, but the coherence of beams can not lead to the change of beam width on propagation.Finally, in Chapter 4, we summarized the work we have done and considered the next work.