Optical Switching in Composite Media Containing Nonlinear Plasmonic Coated Particles with Radial Anisotropy

We investigate the nonlinear optical properties of the composite with identical radial-anisotropic/ nonlinear-plasmonic core-shell spherical inclusions randomly embedded in the linear medium. In the weakly-nonlinear case, the enhanced effective third-order nonlinear susceptibility is achieved through the exhibited surface plasmon resonance, and the enhanced peak can be tuned by adjusting the anisotropic parameter. In the strong-nonlinear case, the single optical bistability, double optical bistability or optical tristability in small particles will be found. Furthermore, we demonstrate the optical multistability arising from the high-order modes in low-index surrounding environment for the large particles. And the anisotropy is essential to expand the diversity of the optical switching. Our results are envisioned for the opportunities of anisotropic materials and the applications of the optical switching.