Performance analysis of a coherent free space optical communication system based on experiment

Area of Science:

• Optical Engineering
• Telecommunications
• Atmospheric Optics

Background:

• Coherent free space optical communication (FSOC) systems are susceptible to atmospheric turbulence.
• Adaptive optics (AO) systems can mitigate turbulence effects.
• Previous studies established the foundation for this experimental AO system.

Purpose of the Study:

• To analyze the performance of a coherent FSOC system using a 97-element AO system.
• To evaluate mixing efficiency (ME), bit error rate (BER), and outage probability.
• To investigate the impact of atmospheric temporal (Greenwood frequency) and spatial (coherent length) characteristics.

Main Methods:

• Utilized a designed experimental AO system with a 97-element continuous surface deformable mirror.
• Conducted performance analysis under varying Greenwood frequencies and atmospheric coherent lengths.
• Measured key performance indicators: ME, BER, and outage probability.

Main Results:

• The influence of atmospheric temporal characteristics on FSOC performance was found to be slightly greater than spatial characteristics.
• This effect was observed given a fixed receiving aperture and number of sub-apertures.
• Specific performance metrics like ME, BER, and outage probability were quantified.

Conclusions:

• Atmospheric temporal turbulence has a marginally stronger effect on coherent FSOC performance than spatial turbulence.
• The findings provide valuable insights for designing robust coherent FSOC systems.
• This research offers a reference for optimizing FSOC system parameters against atmospheric disturbances.