Beam quality evaluation method for vortex light fields based on Wasserstein distance principles

Vortex beams have gained significant attention in recent years due to their unique helical phase distribution and ring-shaped intensity profile, with applications in laser detection, optical micromanipulation, and optical communication. The coherent beam combining (CBC) method enables the generation of vortex beams with higher power. Currently, most beam quality evaluation methods for vortex beams are based on the power-in-the-bucket (PIB) metric, which focuses on energy concentration. To more accurately assess the beam quality of vortex beams produced through the CBC method, we propose a novel evaluation approach based on the Wasserstein distance principle. Subsequently, within the CBC system, the effects of phase errors, positional errors, intensity fluctuations, and timing disturbances on beam combining performance were analyzed. In parallel, the accuracy and stability of the proposed method under these disturbance conditions were thoroughly examined. Comparisons with the PIB-based evaluation method demonstrate that the proposed approach provides a more accurate assessment of vortex beam quality under various perturbation conditions.