Research On Graphene Surface Plasmon Devices In Terahertz Band

Terahertz wave is widely used in communication and devices.It has the dual characteristics of electron and photon.With the rapid development of wireless communication,graphene,as a new core material,provides great help for the development of high frequency communication.However,in the aspect of increasingly miniaturized device integration,new technology support is needed.The surface plasmon has excellent light field localization ability,which can break through the diffraction limit.At the same time,due to the unique band structure of graphene,graphene surface plasmon can well localize the light field and reduce the loss.Therefore,the research on graphene surface plasmon in THz band is of great significance to improve the device performance.The research contents of this thesis are as follows:(1)The electromagnetic properties of graphene were studied.The conductivity,dielectric constant and refractive index of graphene were analyzed.The dispersion relation of surface plasmon polaritons was studied.The dispersion relation of graphene surface plasmon polaritons was deduced.The excitation mode and characterization parameters of surface plasmon polaritons were analyzed.The simulation method used in this paper was briefly introduced(2)A periodic grating structure based on graphene was designed,and the quality factor and effective mode area were used to quantitatively analyze the characteristics of graphene surface plasma.The performance of the periodic graphene grating structure was optimized by optimizing the structure size and material parameters of the grating structure.Then the application prospect of the structure in the filter was analyzed and studied by changing the incident angle of the incident light and adding Anderson local effect.The transmission spectrum of grating structure was obtained by simulation,and the passband and forbidden band of transmission spectrum under different disorder degree and Fermi level were analyzed and optimized to achieve filtering effect.(3)A temperature sensor based on graphene surface plasmon was designed.The principle of temperature measurement was introduced.Then,by analyzing the reflection spectrum characteristics of the model,the grating thickness,grating bottom thickness,grating width and graphene width of the sensor structure to achieve the best temperature measurement effect and surface plasma localization with the most suitable size.On this basis,the temperature sensitivity of ethanol,distilled water and glycerol,which are commonly used in low-cost industry,was calculated.The refractive index of these media changes with temperature was mainly used for simulation.The analysis and comparison show that the sensitivity of the temperature sensor is the highest when glycerol is used as the sensing medium,and the best temperature measurement effect can be achieved.