Unfolding Unstable Skyrmionic Polarization Textures

ABSTRACT Polarization of light can form skyrmionic textures, akin to nonlinear topological solitons in condensed matter, yet their disparate physical context has motivated extensive debate regarding their stability. Such optical polarization textures are usually constructed by superposing two spatial eigenmodes with different polarization. Here we show that the topological charge of such polarization textures (skyrmion number) changes when an arbitrarily small perturbation splits coalescent phase singularities. In a superposition of two vortex beams, the skyrmion number generally only depends on the highest‐order vortex topological charge rather than the difference of charges of the vortices in superposition , which only arises in an idealized case without perturbation. These results have significant implications for polarization structures with wavelength‐scale localization and those experiencing complex aberrations.