Tunable optical bistability and tristability of nonlinear graphene-wrapped dielectric nanoparticles

Based on full-wave scattering theory with self-consistent mean field approximation, we study the optical multi-stability of graphene-wrapped dielectric nanoparticles. We demonstrate that the optical bistability (OB) of the graphene-wrapped nanoparticle exist in both near-field and far-field spectra, and show the optical multi-stability arising from the contributions of higher-order terms of the incident external field. Moreover, both the optical stable region and the switching threshold values can be tuned by changing either the Fermi level or the size of the nanoparticle. Our results promise the graphene-wrapped dielectric nanoparticle a candidate of multi-state optical switching, optical memories and relevant optoelectronic devices.