Optimization criterion for initial coherence degree of lasers in free-space optical links through atmospheric turbulence.

Partially coherent beams can be used to reduce the turbulence-induced scintillation; however, the partial coherence induces the decrease of the mean received irradiance. An optimization criterion for the initial coherence degree of lasers is proposed. This criterion maximizes the received irradiance that occurs with the highest probability. A method for adaptive initial coherence was given to use the criterion in practical applications.