Spatial polarization phase shift keying for high-capacity coherent free-space optical communication

Area of Science:

• Optical communication
• Photonics
• Signal processing

Background:

• Atmospheric turbulence distorts light beams, affecting polarization and phase in free-space optical communication.
• Increasing data capacity in coherent free-space optical communication (CFSOC) is a significant research challenge.

Purpose of the Study:

• To propose and evaluate a novel technique for enhancing data capacity in CFSOC systems.
• To mitigate the effects of atmospheric turbulence on optical communication links.

Main Methods:

• Development of a spatial polarization phase shift keying (SPPSK) technique by combining polarization multiplexing and phase modulation.
• Implementation of a vectorial adaptive optics (V-AO) system to correct polarization and phase aberrations.
• Simulation experiments conducted under simulated atmospheric turbulence conditions.

Main Results:

• The SPPSK technique demonstrated a potential for approximately 20X increase in data capacity for a single CFSOC beam.
• The V-AO system effectively corrected polarization aberrations caused by turbulence.
• A significant decrease in bit error rate (BER) and enhancement in communication performance were observed.

Conclusions:

• The proposed SPPSK technique offers a promising solution for high-capacity CFSOC.
• Vectorial adaptive optics is effective in compensating for atmospheric turbulence-induced distortions.
• This research provides a foundation for developing advanced laser communication systems.