Acta Optica Sinica, Volume. 42, Issue 19, 1916001(2022)
Narrow/Broad Band Switchable Terahertz Absorber Based on Graphene and Vanadium Dioxide Composite Structure
Fig. 1. Schematic diagrams of absorber unit cell. (a) Side view of unit cell; (b) top view of unit cell; (c) schematic of applying voltage to graphene
Fig. 2. Conductivity of graphene at different Fermi levels. (a) Real part of conductivity; (b) imaginary part of conductivity
Fig. 3. Simulated absorption spectra of absorber under different VO2 states
Fig. 4. Absorption spectra and relative impedance of absorbers under different VO2 states. (a) Metallic state; (b) insulating state
Fig. 5. Distributions of surface current and magnetic field of YOZ plane. (a)(e)(i)(m) Current distributions of graphene at four frequency points; (b)(f)(j)(n) current distributions of VO2 at four frequency points; (c)(g)(k)(o) current distributions of metal substrate of structure at four frequency points; (d)(h)(l)(p) magnetic field distributions of air above graphene structure at four frequency points
Fig. 6. Absorption spectra of absorber under different Fermi levels of graphene and different conductivity of VO2. (a) Absorption spectra under different Fermi levels of graphene; (b) absorption spectra under different conductivities of VO2; (c) absorption spectra for varying both conductivity of VO2 and Fermi levels of graphene
Fig. 7. Absorption spectra of absorber with different polarization angles
Fig. 8. Absorption spectra of absorber at different incident angles,and distributions of magnetic field on YOZ plane with different polarization modes and different incident angles at frequency of 0.99 THz. (a) Absorption spectrum for TE polarization; (b) absorption spectrum for TM polarization; (c) distributions of magnetic field on YOZ plane with different polarization modes and different incident angles at frequency of 0.99 THz
Fig. 9. Absorption characteristics for different refractive indices of object to be measured and absorber sensitivity; (a) Absorption characteristics for different refractive indices of object to be measured; (b) absorber sensitivity
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Chengcheng Huang, Yonggang Zhang, Lanju Liang, Haiyun Yao, Wenjia Liu, Fu Qiu. Narrow/Broad Band Switchable Terahertz Absorber Based on Graphene and Vanadium Dioxide Composite Structure[J]. Acta Optica Sinica, 2022, 42(19): 1916001
Category: Materials
Received: Feb. 14, 2022
Accepted: Mar. 30, 2022
Published Online: Oct. 18, 2022
The Author Email: Zhang Yonggang (ygzhang2000@163.com), Liang Lanju (lianglanju123@163.com)