Experimental Study on Long-Distance Atmospheric Propagation Characteristics of Supercontinuum Laser

With the continuous improvement in output power and beam quality, the application scope of supercontinuum (SC) laser sources has been significantly expanded. However, the propagation characteristics of SC lasers in atmospheric environments remain insufficiently studied. In this work, we conducted an 8 km field experiment to quantitatively investigate the propagation behavior of SC lasers through atmospheric turbulence. The measurements focused on intensity fluctuations, scintillation index, and beam wander after long-distance propagation. Numerical simulations based on the Gaussian-Schell model (GSM) were also performed for comparison with the experimental data. The analysis reveals that, under identical propagation conditions, the scintillation index at each SC wavelength is substantially lower than that of a fully coherent laser. Moreover, the far-field scintillation index increases monotonically with off-axis distance. The scintillation behavior of each SC wavelength is found to be similar to that of a monochromatic partially coherent beam with a spatial coherence length on the order of several millimeters. In contrast, the beam wander statistics of SC lasers closely resemble those of monochromatic coherent beams, indicating that beam wander is essentially independent of wavelength and spatial coherence. These findings provide valuable references for deploying SC lasers in free-space optical communication and active optical countermeasure systems.