Spin Hall (SH) shift of light from nanoparticles refers to the transverse displacement of scattered light due to spin–orbit interaction (SOI). Generally, the SH shift is small and suffers from inherent low scattering efficiency. In this paper, the SH shift and its corresponding scattering intensity are simultaneously enhanced for dual nanoparticles. Based on the generalized Lorentz‐Mie theory, the morphology of the nanoparticle is optimized to increase the scattering intensity while preserving the wavelength‐scale SH shift. The simultaneous enhancements are realized by manipulating the electric and magnetic dipolar modes to overlap at their resonances rather than the tails of the scattering. Meanwhile, a new pattern is identified on orbital momentum streamlines, revealing the near field's SOI. In addition, an experiment is proposed to detect the SH shifts in the far‐field observation plane. The scattering intensities from oblate spheroids are enhanced by one order of magnitude compared to the spherical counterparts. The findings may shed new light on the mechanism of light–matter interaction and facilitate the experimental detection of the SH effect of light.

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 spinorbit 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.