Study on the Influence of Atmospheric Light Intensity Scintillation Effect on Optical Fiber Coupling Efficiency

Light intensity flicker is the most basic and important effect of turbulence. Fiber coupling efficiency is the primary parameter that ensures the system’s communication quality. The light intensity flicker effect caused by atmospheric turbulence significantly affects the coupling efficiency of space light in a single-mode optical fiber. Based on the principle of fiber coupling efficiency, this paper first establishes the relationship between light intensity flicker and spatial coherence radius, then analyzes the influence of light intensity flicker on fiber coupling efficiency through the spatial coherence radius. A laser communication system was built, and real-time measurement experiments on atmospheric light intensity flicker and optical fiber coupling efficiency at different transmission distances and altitudes above the ground were completed. The experimental results show that the constructed experimental system can simultaneously measure the scintillation index and fiber coupling efficiency. When the communication distance is 12,000 m and the height is 600 m above the ground, the scintillation index is measured to be 0.63, and the coupling efficiency is 0.05. The results of the study provide an experimental and theoretical basis and data support to promote the development of atmospheric laser communications.