Fiber coupling efficiency through turbulence medium for long and short exposures

Fiber-optic components have been used in high-speed free-space optical communication systems. The received laser beam in such a system must be coupled into a single-mode fiber at the input of the receiver module. However, laser propagation through atmospheric turbulence medium degrades pattern matching and limits the fiber-coupling efficiency. We numerically evaluate the fiber-coupling efficiency for size pattern matching degraded by atmospheric turbulence according to optical resolution for long and short exposures. If just long exposure is corrected little effect on coupling efficiency is improved. And in the case of weak turbulence when receiving aperture is 30cm the fiber coupling efficiency is more than 0.1 with correction system of long exposure.