Nonlinearity-Tuned Optical Spin-Orbit Interaction of Graphene-Wrapped Nanoparticles

Nonlinear control of light-matter interaction plays an important role in various optical phenomena, including spin-orbit interaction of light. In this paper, we demonstrate that the spin-orbit interaction of graphene-wrapped nanoparticles can be tuned by the input intensity of light. Typical optical bistable responses are observed in the scattering efficiency and the local electric fields. In the optical bistable regime, the strength of spin-orbit interaction in the near-field is significantly tuned in the switching-up and switching-down branches. The tunability of spin-orbit interaction enables promising nonlinear control schemes in nanophotonic devices.