Research On Terahertz Regulating Devices Based On Graphene Metamaterials

Terahertz has the advantages of high bandwidth,strong penetration and non-ionizing radiation.It has a wide range of applications in optoelectronics,material analysis,safety detection and other fields.However,the development of terahertz technology is still restricted by many factors,including technical limitations and cost limitations.Terahertz waves have problems such as attenuation,interference,and dispersion during signal transmission.At present,there is no mature terahertz technology and device use.Therefore,the limitations of technology have slowed down the development of terahertz applications.In addition,the technical cost of terahertz devices is high,and most independent devices are restricted by application scenarios.The function is relatively simple,and different devices need to be developed for different scenarios,which greatly increases the cost of terahertz devices.At present,according to the requirements of terahertz applications and application scenarios,research on terahertz devices with active tuning functions has attracted attention.The purpose of this paper is to solve this problem.Based on the characteristics and applications of terahertz technology,the functional properties of metamaterials are studied.With the excellent photoelectric properties of graphene,terahertz control devices based on graphene metamaterials are designed.The main research contents of this paper are as follows :(1)The first chapter mainly summarizes the terahertz technology,focuses on the characteristics and application scenarios of terahertz technology,and analyzes the existing problems in the development of terahertz technology.At the same time,the development history of graphene materials and the progress of metamaterials are also introduced,and the research progress of graphene metamaterials is reviewed in combination with the characteristics of graphene metamaterials.(2)The second chapter mainly introduces the basic theories used in the research,such as the calculation of graphene conductivity and magnetic permeability,the principle of absorber absorption,the FDTD algorithm and the specific process and method of the tools used in the research.(3)In the third chapter,a multi-band terahertz absorber based on graphene metamaterial is designed.It consists of a classic three-layer structure :metal-dielectric-graphene.In the process of simulation,the characteristics of the device in passive tunability are studied by analyzing several cases of material characteristics caused by the change of graphene structure.At the same time,by changing the Fermi level of graphene,the change of the device is analyzed,and the active tunable characteristics of the device are studied.The mechanism of the absorption peak formed by the absorber is well explained by the equivalent circuit theory.The designed absorber has great potential applications in terahertz wave stealth,detection,imaging and other fields.(4)In the fourth chapter,a broadband terahertz filter composed of two parallel graphene strips is studied and designed.The parallel graphene strips are located on the upper and lower sides of the thin and uniform dielectric layer.The simulation results show that the structure can generate broadband filtering effect in the terahertz range.The research can be used as a high-performance terahertz filter or absorber,which is also of great significance for the development of ultra-compact integrated terahertz devices.