Plasmon-modulated bistable second-harmonic generation in a nonlinear microcavity coupled to a metallic nanoparticle

Multiple nonlinear effects with second-harmonic (SH) generation and optical bista-bility (OB) are highly desired but rather rare due to insufficient intrinsic nonlinearity in most nonlinear media. Here, a nonlinear microcavity coupled to a metallic nanoparticle (MNP) is suggested to realize the bistable SH generation. When two counterpropagating driving fields are injected into the cavity, a traditional SH pathway is constructed via the two-photon process of fundamental-harmonic (FH) photons. In addition, we report the coexistence between the SH and OB effects under the condition that the strong excitation and the detuning management for the driving fields boost system nonlinear responses. In the presence of a control field toward the MNP, our calculation finds that the traditional and plasmon-induced SH pathways in the present system allow enhancing the SH conversion efficiency and reducing the OB thresholds simultaneously. With the control field intensity increasing, a linear growth rate for the SH efficiency maximum is achieved. Furthermore, the relative phase between the driving and control fields has profound effects on modulating the bistable SH efficiency, the bistable interval and the thresholds. (c) 2023 Optica Publishing Group under the terms of the Optica Open Access Publishing Agreement