title: Fiber-coupling efficiency for free-space optical communication through atmospheric turbulence.
abstract: High-speed free-space optical communication systems have recently used fiber-optic components. The received laser beam in such a system must be coupled into a single-mode fiber at the input of the receiver module. However, propagation through atmospheric turbulence degrades the spatial coherence of a laser beam and limits the fiber-coupling efficiency. We numerically evaluate the fiber-coupling efficiency for laser light distorted by atmospheric turbulence. We also investigate the use of a coherent fiber array as a receiver structure and find that a coherent fiber array that consists of seven subapertures would significantly increase the fiber-coupling efficiency.
authors.affiliation: Department of Electrical and Computer Engineering, Johns Hopkins University, 105 Barton Hall, 3400 North Charles Street, Baltimore, Maryland 21218, USA. yamac@jhu.edu
authors.forename: Yamaç
authors.initials: Y
authors.lastname: Dikmelik
authors.forename: Frederic M
authors.initials: FM
authors.lastname: Davidson