The Research Of The Impact Of Atmospheric Turbulence On The Space Lingt-Single Mode Fiber Coupling Efficiency

Free space optical communication has a huge advantage over microwave communi-cation, and now it has aroused more interests of people. Nowadays, fully utilized the existing mature fiber-optic communications technology is a trend for wireless optical communication technology development. However, how to improve the space light-single mode fiber coupling efficiency is a critical issue we need to resolve first. On this objective, in this paper, the theoretical analysis of the effect of atmospheric turbulence on the space light-single mode fiber coupling efficiency is discussed. On this basis, the short-distance experiment coupling space light into single mode fiber is carried out.1. The main factors affecting the process coupling space light into single mode fiber are analyzed.This paper introduced the statistical theory of atmospheric turbulence and gave out the main turbulence parameters and meteyard based on the theory of the space light-single mode fiber coupling efficiency under ideal conditions. The affects of excursion on the coupling efficiency were introduced.2. The influence of atmospheric turbulence on the space light-single mode fiber coupling efficiency is analyzed and simulated.In the weak turbulence condition, mathematical model of the mean coupling efficiency and its fluctuation variance was given. And the fluctuation variance of coupling efficiency was simulated studied under the atmospheric conditions. The influences on the average coupling efficiency was theoretically studied, which were induced by the structure constant of atmospheric refractive index, the diameter of coupling lens and the single-mode fiber mode field radius.3. Validating the theoretical model by a experiment under a short link coupling condition.We analyzed the impact of atmospheric effects on the efficiency by coupling the space light into a single mode fiber after a short link transmission. The experimental results proved validity of the theory on the whole. And the experimental research for coupled power found that along with drop of the relative fluctuation of coupling efficiency, the mean coupling efficiency raise when diameter of the lens is near to the optimum diameter.The results of this paper lay the theoretical and experimental foundation for indeed establishing the efficient space light-single mode fiber coupling systems.