Influence of atmospheric turbulence on coherent source in a horizontal long-distance laser link

Abstract

In coherent optical communication, the application of linearly polarized light can greatly improve communication sensitivity and communication capacity. However, when a laser transmits in an inferior atmospheric layer, the polarization character is influenced by atmospheric turbulence. This study proposes a measurement experiment of the characteristics of linearly polarized light over an 11.16-km turbulent path. We also present a theoretical approach and its operation for investigating the polarization characteristics of a laser. The variations of polarization under different atmosphere link distances and turbulence intensities are also discussed. The experimental results were in agreement with the theoretical analysis results. The theoretical analysis and experimental results show that the effect of atmospheric turbulence on polarization direction is stronger than that of atmospheric turbulence on the polarization state. This work will benefit coherent free-space optical communication system design efforts.