Study Of Metamaterial-based Tunable Absorber At The Terahertz Region

Terahertz(THz)wave has many unique properties and has a broad application prospect in many fields such as electronics,communication,medicine,environment,etc.In recent years,functional devices in THz band have become a new research hotspot,and the emergence of metamaterial has made the THz related technology further developed.Metamaterial is a kind of artificial composite material with periodic element structure,and its singular electromagnetic properties make it have wide application value.In this paper,two kinds of metamaterial absorbers working at the THz region are proposed,and the proposed absorbers are studied from several perspectives.The main research contents are as follows:1?A tunable dual band THz absorber is proposed.A graphene plane is added to the traditional three-layer structure.The simulation data shows that the absorber has two resonance absorption peaks.By adjusting the graphene's Fermi level,the low-frequency absorption peak achieves a blue shift of 1.43 THz and the high-frequency absorption peak achieves a blue shift of 1.02 THz,And the absorption rate of more than 95% can be achieved at the peak of the two absorption bands.In addition,the performance changes of the absorber when the structural parameters are changed and absorption mechanism are both analyzed.2?A broadband THz absorber is proposed,which is composed of metal substrate,double-layer polyimide dielectric,double-layer silicon dielectric and metal resonance ring.To obtain the tunable broadband absorber,a graphene pattern is added to the metamaterial layer.The broadband terahertz absorber can achieve an absorption of higher than 90% in the range of 2.65 ? 8.05 THz.When the Fermi level of graphene varies from 0 e V to 0.6 e V,the absorption peak of the tunable absorber can achieve a blue shift of 1.26 THz,and the maximum absorption band can reach 1.96 THz.3?The absorption spectrum of tunable broadband terahertz absorber when changing the structural parameters is analyzed,and the absorption mechanism of the two broadband absorbers is compared.Further data shows that both absorbers are insensitive to polarization and can work under a large incident angle range.