Error-rate measurements in an atmospheric twin-channel optical link

The error rate has been measured for an atmospheric twin-channel polarization modulated optical link in order to ascertain the applicability of a photon-counting digital model to the design of a simple realistic system. Error probabilities in the range
10^{-2}-10^{-7}
at 76 Mb/s were measured in different atmospheric conditions, for a path of 3.6 km. The agreement between experimental results and theoretical ones is satisfactory and justifies the use of the model in the design.