Reconfiguring optical skyrmion topology in free space

Skyrmions, topological particle-like spin textures, have drawn significant interest in optics for their potential applications in robust information encoding and photonic manipulation. However, in free space, conventional skyrmionic beams suffer from passive and deterministic transformations in topological textures during propagation due to the Gouy phase effect, consequently limiting their stability and controllability. Here, we experimentally construct customizable Stokes skyrmions, providing unprecedented control over topologies (including skyrmion number and texture helicity) and propagation trajectory. This approach not only ensures the stable preservation of skyrmion textures over long distances but also enables customized transformations between distinct skyrmion types—anti-skyrmions, bimerons, and higher-order skyrmions—without relying on physical transformation elements. More importantly, we realize perfect optical skyrmions experimentally for the first time, to our knowledge. Additionally, we demonstrate the experimental generation of skyrmions along self-accelerating arbitrary trajectories, including parabolic and spiral paths. This work establishes a robust and reconfigurable platform for the manipulation of topological light fields, with significant implications for high-capacity optical coding, encryption, and precision particle manipulation.