Research On Plasmon Induced Transparency Phenomenon Based On The Metasurface Of Two-dimensional Materials

Electromagnetically induced transparency(EIT)is a quantum interference effect discovered in an atomic system firstly,which can cause the decrease of the light absorption efficiency at the resonant absorption frequency,and even complete transparency.However,the implementation conditions of the traditional quantum EIT are very harsh,which imposes greater constraints on practical applications.Plasmon induced transparency(PIT),an electromagnetically induced transparency(EIT-like)similar to atomic systems,has attracted attention from researchers.At present,it has potential application prospects in polarization switches,slow-optical devices,optical sensors and other fields.This paper uses the Finite Difference Time Domain method to study the PIT phenomenon and its physical mechanism in the graphene and black phosphorus metasurface.The main contents are as follows:(1)A dynamic tunable PIT effect based on the controllable polarization state of the two-dimensional graphene metasurface is designed,and the transparent window can be dynamically adjusted by changing the relevant structural parameters of graphene or the Fermi energy level.Moreover,the n?mber of transparent windows can be switched between 1 and 2 by adjusting the polarization direction of the light,without the need to reconstruct the structure.Our proposed graphene-based metasurface structure provides a PIT multifunctional control system for studying slow-light effects,optical sensing and selective filtering characteristics.(2)A device composed of a pair of parallel graphene strips and two split rectangular graphene ring resonators is used to realize the PIT phenomenon in the mid-infrared region.The window of PIT is actively tuned by adjusting the geometric parameters of graphene and Fermi energy.In addition,the design of the device can obtain a good slow light effect,and the group delay can reach0.06 ps.In addition,the peak frequency of the transmission window is very sensitive to the refractive index of the medium.The PIT system designed based on graphene metamaterials has a refractive index sensor with a sensitivity of about 6800nm/RIU,and the design provides a viable platform for high-sensitivity sensors and slow-light devices.(3)A composite structure composed of a patterned single-layer black phosphorous(black phosphorous,BP)sheet sandwiched by a dielectric layer is proposed,which can achieve plasma-induced transparency(PIT)effect in the mid-infrared band.The physical mechanism of the PIT effect originates from the near-field coupling between the bright mode existing in the horizontal parallel BP strips and the dark mode existing in the vertical parallel BP strips.By changing the geometric parameters and carrier concentration of black phosphorus,the PIT effect can be actively adjusted.In addition,the proposed structural system has strong dispersion,with a group index of ~15,which provides a new strategy for slow optical devices.