Propagation and Focusing Properties of Vortex Beams Based on Light Ray Tracing

By using the ray-tracing method based on geometric optics, we studied the propagating and focusing characteristics of vortex beams with a top-hat intensity distribution. An intuitive mathematical model is established for the propagation and focusing of vortex beams, revealing the mechanisms and physics underlying the spatial evolution, e.g., the dark spot formation in the center of a vortex beam, the relationship between the radius of the dark spot and the propagation distance, and the rotational angle varying with the propagation distance for an azimuthal asymmetric vortex beam. The experimental observations are consistent with theoretical predictions. The results and findings are helpful in intuitively understanding the propagation and evolution of specific vortex beams; therefore, they are of significance for explorations of the novel properties of twisted vortex beams and their applications.

Automated summary

By using the ray-tracing method, this study investigated the propagation and focusing characteristics of vortex beams with a top-hat intensity distribution. A mathematical model was established to understand the mechanisms underlying the spatial evolution of these beams. Experimental observations were consistent with theoretical predictions, providing valuable insights into the propagation and evolution of vortex beams.