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With the development of optical fiber communications, especially
the maturity of the optical amplifiers and the WDM technology, space optical
communication at 1550 nm becomes a promising solution for future high
speed satellite communication. Receiving technology with optical amplifiers
and coupling space light into single mode fiber are key technologies in space
optical communication at 1550 nm. Free-space-to-fiber coupling technique
investigated in this paper is the first challenge of applying fiber communication
techniques to free space optical communications. We analyzed the factors
that affect the efficiency of free-space-to single-mode-fiber coupling based on
mode-matching theory of electromagnetic fields. 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.
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.
The results of this paper lay the theoretical and experimental foundation for
indeed establishing the efficient space light-single mode fiber coupling
systems.
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