Low-power and ultrafast all-optical tunable plasmon induced transparency in metal-dielectric-metal waveguide side-coupled Fabry-Perot resonators system

In this paper, low-power and ultrafast all-optical tunable plasmon induced transparency in metal-dielectric-metal (MDM) waveguide side-coupled Fabry-Perot (FP) resonators system with nonlinear optical Kerr medium is investigated both analytically and numerically. High tunability in transparency window magnitude and phase responses is obtained when nonlinear optical Kerr material is embedded in the MDM waveguide. In order to reduce the pump intensity, traditional nonlinear optical Kerr material is replaced by graphene. A shift of 64 nm in the central wavelength of the transparency window is achieved when the FP resonators are covered with monolayer graphene with pump intensity increasing from 9.2 to 10 MW/cm2. An ultrafast response time of the order of 1 ps is reached because of ultrafast carrier relaxation dynamics of graphene. This work not only paves the way towards the realization of on-chip integrated nanophotonic devices but also opens the possibility of the construction of ultrahigh-speed information processing chips based on plasmonic circuits.