Dynamic Regulation Of Terahertz Wave Based On Graphene/Metal Composite Metasurface

Terahertz wave is an ideal band for 6G broadband wireless communication in the future because of its broadband.Therefore,the research of terahertz functional devices has become one of the research hotspots in the current international academic circles.The dynamic regulation of terahertz wave amplitude and phase is the key link in the application of terahertz technology.Due to the poor response characteristics of traditional materials in terahertz frequency band,it is difficult to meet the needs of rapid regulation of terahertz wave parameters.Graphene is a new two-dimensional material with excellent physical properties and photoelectric tunability of Fermi level.It has important application value in the dynamic regulation of terahertz wave parameters.This paper focuses on the terahertz wave dynamic control device based on graphene / metal composite metasurface.The main contents are as follows:1.The energy band characteristics and regulation mechanism of graphene are studied,which provides a theoretical basis for the design of terahertz wave amplitude and phase dynamic regulation devices based on graphene metal composite metasurface.2.A terahertz amplitude dynamic modulator and two terahertz phase dynamic control devices are designed.(1)The designed dynamic regulator of terahertz wave amplitude can dynamically adjust the transmission of terahertz wave between 98 % and 34 % by adjusting the Fermi level of graphene.Moreover,the adjustable range is from 1.49 THz to 4.05 THz,realizing ultra wideband regulation.(2)By adjusting the Fermi level of graphene,the phase of the designed transmission terahertz wave dynamic regulator reaches 180° at 4.3 THz,and the average efficiency is as high as 27 %.(3)The designed reflective all phase regulator has a phase of 360° at 1.09 THz.Moreover,the efficiency of the reflective 180° phase regulator is more than 20 %.3.The application of reflective all phase regulator in terahertz beam deflection and focusing is studied.The structural parameters of reflective all phase regulator are verified by numerical simulation.4.The preparation method of reflective modulator is studied.The modulator samples were prepared by micro and nano processing processes such as coating,transfer graphene and lithography,and the performance was tested by terahertz time domain spectroscopy system.The test results are close to the simulation results.In this paper,the terahertz wave dynamic control device based on graphene / metal composite metasurface is expected to be applied to terahertz broadband communication,detection,sensing,holographic imaging,lens and phased array antenna,which plays an important role in promoting the development of terahertz technology.