Optical skyrmions in Poisson spots

Skyrmions, topological spin textures, have been extensively studied across disciplines, including particle physics, quantum fields, condensed-matter physics, and optics. Optical skyrmions have recently promised topologically enhanced light–matter interaction, sensing, and information processing. However, the generation of which typically requires complex structured media or intricate wavefront engineering. Here, we unveil that a well-known optical diffraction phenomenon—the Poisson spot—can host a rich variety of skyrmionic topologies simultaneously, which are constructed by multiple degrees of freedom of light, including optical spin, polarization Stokes vectors, and electric and magnetic fields. We also experimentally demonstrate the coexisting electric field, spin and Stokes skyrmions, and magnetic field skyrmions can be derived from electric field skyrmions via electromagnetic duality symmetry. Our approach is strikingly simple but enables tunable multidimensional topological control, overcoming the intrinsic complexity of electromagnetic fields.