Measuring the effect of real atmospheric turbulence on coherent free-space optical communications links

The development of coherent free-space optical communications (FSOC) systems could provide an opportunity for significantly increased data rates and improved security compared to conventional radio frequency (RF) systems in the domain of wireless communications. One key challenge in the implementation of FSOC systems is the characterization and mitigation of atmospheric turbulence present in the optical channel. In this work, we present experiments demonstrating coherent free-space optical communications over an outdoor free-space link with data rates on the order of gigabits per second (Gbit/s). By simultaneously recording the laser spot of the received signal and the bit error ratio (BER) in the link, we measure both, the strength of atmospheric turbulence and the quality of data transmission, in an attempt to quantify the effect of the former on the latter.