title: Turbulence-induced channel crosstalk in an orbital angular momentum-multiplexed free-space optical link.
abstract: A multichannel free-space optical (FSO) communication system based on orbital angular momentum (OAM)-carrying beams is studied. We numerically analyze the effects of atmospheric turbulence on the system and find that turbulence induces attenuation and crosstalk among channels. Based on a model in which the constituent channels are binary symmetric and crosstalk is a Gaussian noise source, we find optimal sets of OAM states at each turbulence condition studied and determine the aggregate capacity of the multichannel system at those conditions. OAM-multiplexed FSO systems that operate in the weak turbulence regime are found to offer good performance. We verify that the aggregate capacity decreases as the turbulence increases. A per-channel bit-error rate evaluation is presented to show the uneven effects of crosstalk on the constituent channels.
authors.affiliation: Department of Electrical and Computer Engineering, College of Optical Sciences,University of Arizona, Tucson, Arizona 85721, USA. janguita@ece.arizona.edu
authors.forename: Jaime A
authors.initials: JA
authors.lastname: Anguita
authors.forename: Mark A
authors.initials: MA
authors.lastname: Neifeld
authors.forename: Bane V
authors.initials: BV
authors.lastname: Vasic