Research On Electromagnetic Coupling Theory And Device Design Based On Graphene Metamaterials

In the 21 st century,the rapid development of information technology puts forward higher requirements for the integration and miniaturization of devices.Photon bans electrons and serves as an information carrier is the development trend of optical communication equipment.The construction of compact optical circuits/devices wi th breakthrough diffraction limits based on surface plasmon polariton(SPPs)makes i ntegration and miniaturization of new photonic devices possible.The application pr ospects of SPPs in sub-wavelength optics,microscopy,data storage and biophotonics are gradually being explored.In this paper,the finite-difference time-domain method is used to study the graphene plasmon-induced transparent device and the perfect superabsorbent device.The main research contents and arrangements are as follows:In the mid-infrared band,a dynamically tunable plasmon-induced transparent device realized by an H-shaped graphene structure is proposed.The lateral displacement of the intermediate graphene strip breaks the symmetry of the structure and excites the magnetic dipole resonance that is not achievable in the symmetrical structure.The strong coupling of the out-of-phase current between the upper and lower cavities of the resonator causes a transmission peak to appear at the resonant wavelength position of the original transmission valley.The control of the transparent window can be realized by changing the structural parameters and the Fermi level.The study is available with a FOM value of 17.78 and a sensitivity up to 8 ?m/RIU.In addition,a group delay of 0.04 ps can be achieved in the transparent peak window,which results in a unique slow light effect.Undoubtedly,this work provides a good platform for deve loping compact infrared plasma components such as switches and sensors.A double-band metamaterial absorber realized by a sandwich structure of an L-shaped graphene strip-medium-metal reflective layer is proposed.The simulation results show that the absorber exhibits two resonance peaks in the mid-infrared region,and its absorption rate is greater than 98.77%.The electromagnetic eigenmode resonance of a single L-shaped graphene strip induces two absorption peaks with an average absorption of about 50%.The two asymmetric L-shaped graphene strips are assembled together,and the absorption rates of the two absorption peaks are close to 100% due to plasmonic couplings.The position of the spectral absorption peak can be dynamically adjusted by adjusting the Fermi energy and the refractive index.In add i-tion,the influence of optical polarization angle on absorption characteristics is studied.This kind of adjustment mechanism is more flexible and has broad application pr ospects in detection and electromagnetic wave energy storage.