Development of adaptive optical correction and polarization control modules for 10-km free-space coherent optical communications

In this work, we developed an adaptive optical correction module and polarization control module to compensate for the effects of atmospheric turbulence on long-distance free-space coherent optical communications. We established a coherent optical communication system based on heterodyne differential binary phase-shift keying modulation in Xi’an University of Technology, China, to achieve video transmissions over a long distance of 10.2 km. Indeed, the modules resulted in a baseband signal with a more regular pattern with a significant decrease in burrs and the polarization state of the optical signal was effectively controlled, which verifies the usability of the modules.