Temperature-dependent tunable terahertz metamaterial absorber for the application of light modulator

Publication date: Available online 13 October 2018Source: Results in PhysicsAuthor(s): Dan Li, Hailong Huang, Hui Xia, Jianping Zeng, Hongjian Li, Ding XieAbstractA temperature-dependent tunable metamaterial absorber (MA) based on strontium titanate (STO) is proposed at terahertz regions. The MA is a three-layer structure, which is composed of double metallic split-ring resonators (SRRs), silicon substrate, and the ground metallic layer. Numerical results show that the single-band high absorption with the coefficient of 99% is achieved at the frequency of 1.23 THz, and the position of resonant frequency is blue-shifted by increasing the ambient temperature to control the relative permittivity of STO material, which is embedded into two slits of SRR. Moreover, it is found that the absorption efficiency of MA can be tuned by changing the conductivity of vanadium dioxide (VO2) through ambient temperature. Considering the limitation of single-band absorption, a simple method is proposed to achieve dual-band high absorption by rotating the top SRR layer at different angles α. The two high absorption efficiencies of 100% and 97% at the frequency of 1.28 THz and 1.43 THz, respectively, can be obtained when α = 45°. The proposed MA can be used in some areas in term of sensors, light modulators and terahertz absorbers.

Source: Results in Physics - October 15, 2018 Category: Physics Source Type: research