Topological Evolution of Optical Skyrmions via Poincaré Sphere Mapping

ABSTRACT Optical skyrmions are topologically protected spin textures in structured light, whose continuous and versatile control is central to advancing topological photonics and enabling robust optical functionalities. Here, we establish a universal geometric framework for the continuous transformation of stokes skyrmions via the evolution of orthogonal polarization bases on the Poincaré sphere. We show that basis rotations induce deterministic rotations of local spin vectors across the entire field, enabling a unified description of topological evolution. This mechanism is purely geometric and independent of both topological charge and global phase, revealing a previously unexplored degree of freedom for topological control. Experimentally, we realize this framework using cascaded wave plates, achieving complete and reversible conversion among bimerons, skyrmions, intermediate states, and anti‐skyrmions within a single platform, and extending to higher‐order multi‐meron configurations. Our results provide a deterministic route for engineering complex topological spin textures and establish a direct link between polarization geometry and real‐space topology, opening new opportunities for programmable topological photonics.