Optical Skyrmions Modulation Based on Polarization Helicity

In recent years, optical skyrmion has become a research hot spot because of its unique topological property, its flexible modulation technique is needed in the practical application fields. In this paper, by introducing the polarization helicity which characterizes the global twisted distribution of the polarization state, we investigate the spin skyrmion topological state modulation in the tight focusing of the radially polarized vortex light. We show that, the Néel-Bloch-Néel transition of the spin skyrmion texture can be realized in the focal plane. More interestingly, besides the stable spin Néel-type and the Bloch-type skyrmion can be obtained when the initial phase of incident polarization state takes some specific values, its handedness also can be well controlled. The global twisted polarization distribution plays a key role in the spin skyrmion texture modulation and the light-matter interaction. Our results provide a new idea for the dynamic modulation of spin skyrmion and have potential applications in the field of the nanophotonics and the metrology.