Optical skyrmionium of confined partially coherent beams with orbital angular momentum.

In recent years, optical skyrmions have garnered significant attention due to their unique properties and potential applications. These skyrmions, which include optical field skyrmions, optical spin skyrmions, and optical Stokes skyrmions, exhibit deep-subwavelength and topologically stable characteristics that make them highly suitable for various technological applications such as microscopy, metrology, sensing, and memory. In this context, we present a theoretical proposal for the generation of optical spin skyrmions in a tightly focused partially coherent beam. Our study delves into the behavior of these skyrmions as a function of the coherence length of the beam. Optical spin skyrmions fabricated by spin-orbit coupling of a partially coherent optical vortex are not limited by the topological charge m of the optical vortex. This investigation is particularly novel as we believe it marks the first instance where skyrmions have been identified in a partially coherent beam.