Figure 7.

(a) The model of graphene waveguide integrated with stub nanoresonator loaded with core–shell NW. (b) The relative position between energy gaps and band offsets of InAs-ZnS bulk semiconductors, where $E_{V1}=-4.55\mathrm{eV}$ for the top of the valence band and $E_{C1}=-4.2\mathrm{eV}$ for the bottom of the conduction band in InAs; $E_{V2}=-6.52\mathrm{eV}$, $E_{C2}=-2.98\mathrm{eV}$ the same in ZnS; the Ladder-type interaction scheme of two SPP modes with frequencies ${\omega }_1$ (pump) and ${\omega }_2$ (signal); and $9.9\mathrm{nm}$ core radius InAs/ZnS NW with energy levels $E_{\left|1\right.〉}=-4.55\mathrm{eV}$, $E_{\left|2\right.〉}=-4.063\mathrm{eV}$, and $E_{\left|3\right.〉}=-3.908\mathrm{eV}$.