| Satellite laser communication is a new and advanced technology of satellite communication, which has some potential advantages, including higher data rates, larger communication capability, better anti-disturbance, low probability of intercept, less volume, less mass, lower power consumption, no restrictions for frequency use, and so on. Owing to these advantages, since 1960s, some developed countries, such as America, many member countries in Europe, Japan, etc., and some developing countries have begun to investigate and develop the technology of satellite laser communication. By persisting work for half of a century, spatial experiments of inter-satellite and ground-satellite laser communications have successfully performed. And now, based on the achievements of the space experiments, these countries are preparing to promote this technology to practical and commercial applications.Satellite-to-ground link is a primary one for satellite communication network. Therefore satellite-ground laser communication has been widely and deeply researched. Since the atmosphere is one part of its commnication channel for satellite-to-ground laser communication, atmospheric turbulence must give an effect on the performance of its systems and the establishment and stability of the links. It is significant to investigate the atmospheric turbulent effects and their influence on satellite laser communication for the design of satellite laser communication systems, experiments on the track, and practical applications.To date, most studies on the atmospheric turbulent effects and their influence on satellite laser communciation systems are concerned with the Kolmogorov turbulence, because this model is very simple and has been confirmed in the boundary layer by a bulk of experiments. However, the measurements for atmospheric turbulce have shown that the atmospheric turbulence in the troposphere is the Kolmogorov turbulence, while the atmospheric turbulence in the stratosphere (including the tropopause) is another one, namely non-Kolmogorov turbulence. At the same time, the theoretical investigations have also shown that the Kolmogorov turbulence is not the only possible turbulent model in the atmosphere, where Non-Kolmogorov turbulence exists. Therefore, it does not accord with the practical situation of turbulence in the satellite-ground link to consider the turbulenc in the whole link as the Kolmogorov turbulence. Naturally, it becomes a scientific problem solved urgently to investigate the atmospheric turbulent effects and their influence on satellite laser communication based on the practical situation of the atmospheric turbulence in the satellite-ground link.In this dissertation, according to the research status of the atmospheric turbulent effects and their influence on satellite laser communication, non-Kolmogorov turbulent effects and the influence of practical turbulence in the satellite-ground link on satellite laser communication are systematically studied, which includes the following aspects:1. Theoretical research on Non-Kolmogorov atmospheric turbulent effect Based on a Non-Kolmogorov turbulent refractive-index fluctuations power spectrum density, the influence of non-Kolmogorov turbulence on optical wave is studied, which includes the following three aspects:1) Established the theoretical model for the variance of beam wander of laser beam propagating in non-Kolmogorov turbulence. Using geometric optics approximation, the variances of beam wander for collimated and convergent beams in the weak-fluctuation regime have been derived and the analytical expressions have been obtained.2) Established the theoretical model of angle-of-arrival fluctuations for optical wave propagating in the weak non-Kolmogorov turbulence, which includes the following three aspects:(1) Using the spectrum analytical mothed, the variances of angle-of-arrival fluctuations for plane and spherical waves propagating in non-Kolmogorov turbulence have been investigated and the analytical expressions have been obtained.(2) Using the spectrum analytical mothed, the influence of outer scale of non-Kolmogorov turbulence on angle-of-arrival fluctuations for plane and spherical waves propagating in non-Kolmogorov turbulence have been investigated and the analytical expressions containing the inner and outer scales of non-Kolmogorov turbulence have been obtained.(3) The temporal characteristics of angle-of-arrival fluctuation for plane and spherical waves propagating in non-Kolmogorov turbulence have been investigated. The temporal frequency spectra for plane and spherical waves have been derived and the analytical expressions have been obtained.3) Established the theoretical model for amplitude or irradiance fluctuations for optical wave propagating in the weak non-Kolmogorov turbulence, which includes the following two aspects:(1) The log-amplitude variance for a Gaussian-beam wave propagating in non-Kolmogorov turbulence are derived and the analytic expressions have been obtained. Then, for the special beam form, for instance, a collimated beam, a convergent beam, and a divergent beam, more tractable analytic expressions have been obtained respectively.(2) The temporal characteristics of irradiance fluctuations for plane and spherical wave propagating in non-Kolmogorov turbulence has been studied. The temporal frequency spectra have been derived and the analytic expressions have been obtained.2. Research on the influence of Non-Kolmogorov turbulence on satellite laser communications for satellite-ground links The theoretical model for optical wave propagation in combined atmospheric turbulence for ground-satellite laser communication is established.Using a combined atmospheric turbulent model for the refractive-index fluctuations, the combined influences of the Kolmogorov turbulence in the troposphere and non-Kolmogorov turbulence in the stratosphere on satellite laser communication are studied, and the long-term beam spread, scintillation index, and error bit rate for the uplink and downlink channels are analyzed respectively.In this dissertation, our works are a basic applicable investigation concerned with the influence of atmospheric turbulence on satellite laser communication. By theoretical analyses and numerical simulations, the influence of atmospheric turbulence on satellite based on the practical situations of atmospheric turbulence in the satellite-ground link is studied to provide the foundation of satellite laser communication system design. Therefore, the results of this dissertation will not only develop and enrich the theory of optical wave propagation in the atmospheric turbulence but also contribute the development of satellite-ground laser communication.
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