Research On Graphene Metamaterials Based On Surface Plasmon Exciton And Its Absorption Characteristics

In recent years,graphene has become a research focus due to its unique properties.The graphene array can adjust the Fermi level_FE,relaxation time?,incident light angle?,and structural geometric parameters to achieve effective control of light wave absorption,which has great guiding significance for the design of tunable light absorbers.This paper proposes a tunable light absorber composed of a periodic"arrow"graphene arrays,which works in the far infrared and terahertz bands and is analyzed by the Finite Difference Time Domain(Finite Difference Time Domain,FDTD).The simulation results show that the absorption peak increases with the increase of the Fermi level while the other structural parameters are constant.At the same time,other parameters are unchanged.When the relaxation time?and the incident angle?of the light wave change,the resonance wavelength remains the same,but the absorption peak changes.In addition,based on this structure,a structure composed of bisymmetric“arrow”type graphene arrays is also designed and studied in this paper.Therefore,all absorption spectra obtained by calculation and analysis have two peaks,which can achieve the purposes of selective absorption and individual modulation.The research results can be applied to the fields of label-free biomedical sensing,photodetector and photonic device design.The main work of this article is as follows:1.First,a"single arrow"graphene array structure is designed,and the geometric parameters of the structure,Fermi level_FE,relaxation time?,and incident light angle?on the light absorption are studied.The absorption characteristics of the structure are analyzed.The results show that when the Fermi level_FE increases,the resonance wavelengths shift to the left,that is,blue shift.At the same time,the absorption rate at the resonance wavelength correspondingly increases by 12 times.The research results have good potential applications in wavelength absorbers and integrated optics.2.Based on the"single arrow"absorber,the bisymmetric"arrow"graphene arrays are designed and compared,and the absorption characteristics of the structure are analyzed.The results show that when the_FE increases,the absorption peak of the structure also becomes larger,and the resonance wavelength shifts to the left in turn.When the other parameters are constant and the relaxation time is increased,the resonance wavelength does not change and the absorption peak-to-peak value increases.This design provides the possibility of highly adjustable graphene micro-nano surface plasmon components.