All-Optical Strong Coupling Switches Based on a Coupled Meta-atom and MIM Nanocavity Configuration

Abstract

Based on a coupled meta-atom and metal-nonlinear dielectric-metal nanocavity, nonlinear all-optical strong coupling switches are proposed and numerically investigated. In the absence of the external pumping light, the resonances of the meta-atom are continuously tuned across the one of the nanocavity by changing the size of the meta-atom. The meta-atomic electric dipole and quadrupole interaction with the plasmonic nanocavity is obtained. The characteristic anticrossing behaviors manifest the occurrence of the strong coupling. With the resonance of the meta-atom being tuned to the one of the nanocavity, we dynamically tune the coupled strength of the system by changing intensity (power) of the pumping light and realize the transition from the strong coupling regime to the weak one. This means that this system can be used as an on/off switch in which the strong coupling can be on/off with an external control light, and the on/off states correspond to strong/weak coupling regime, respectively. Such a strong coupling all-optical switching is of considerable interest for applications in nanoscale plasmonic circuits.