Design And Application Of Terahertz Sensor Based On Metamaterial

Terahertz wave has the characteristics of low photon energy,strong penetration and fingerprint spectrum,which makes terahertz technology more advantageous than traditional sensing technology in detecting biochemical molecules.However,terahertz technology still has some problems such as low sensitivity in detecting trace analytes,which hinder its wide application.The emergence of metamaterial and the development of micro and nano technology in processing provide a new way for this problem.Therefore,three Terahertz metamaterial sensors are designed and their electromagnetic response characteristics and sensing performance are studied.The main contents are as follows:1.Firstly,Two dual band Terahertz metamaterial sensors were designed.The first is a Terahertz metamaterial sensor based on the transmission.For TE-polarized electromagnetic waves,the sensor has two resonant peaks at 0.614 THz and 1.019 THz.The sensitivity of the sensor is 124 GHz/RIU,202 GHz/RIU,Q value factor is 12 and13 and FOM value is 2.48 and 2.56,respectively.The sensor has good sensing performance,simple structure and easy in processing.The second is a Terahertz metamaterial sensor based on narrow band absorption.The sensor solves the problem of insensitive polarization and achieves almost 99% absorption at 1.662 THz and 1.888 THz.The sensitivity of the sensor is calculated to be 351 GHz/RIU and 287 GHz/RIU,respectively.The Q factor is 213 and 178,FOM value is 45 and 27,respectively.Through analysis,it is found that the two metamaterial sensors can realize multi-point information matching of analytes with different refractive indexes,improving the accuracy and sensitivity of sensors and being applied in the field of sensing.2.A graphene Terahertz metamaterial sensor based on the electromagnetically induced transparency(EIT)is designed.To solve the polarization angle sensitivity and wide angle incidence,The sensor is designed by the design of center symmetry structure.The frequency and amplitude of the sensor can be adjusted by using the electrically adjustable properties of graphene.The sensitivity of the sensor is 832 GHz/RIU,the Q factor is 17.23 and FOM value is 6.4.The sensor characteristics are better than those of the same type of sensors.It lays a certain foundation for the design of sensor.3.In order to verify the feasibility of metamaterial sensor,an axisymmetric Terahertz metamaterial sensor based on transmission is fabricated and tested.The experimental result is consistent with the simulation result.In addition,the dielectric constants of water,anhydrous ethanol and ethylene glycol are measured based on the sensor.The analysis result shows that the metamaterial sensor can not only distinguish the different dielectric constants of the solutions,but also obtain the real part of the dielectric constant of the solutions through inversion.Three Terahertz metamaterial sensors are designed in this paper.All of them have remarkable sensing properties.Terahertz metamaterial sensor based on transmission has been processed and tested,and the dielectric constant of the sample has been measured.