Fig. 1. Structure diagram of perfect absorber structure in terahertz band ^[9]. (a) Metamaterial layer on top of polyimide gasket; (b) underlying metal cutting lines on GaAs wafers; (c) a cell structure containing an intermediate layer (polyimide)

Fig. 2. Metamaterial absorber. (a) Multi-reflection and transmission model^[16]; (b) reflection and transmission coefficients at air-dielectric interface

Fig. 3. (a) Structure diagram and (b) absorption spectra of terahertz metamaterial perfect absorber proposed by Tao et al.^[13]; (c) structure diagram and (d) absorption spectra of terahertz metamaterial perfect absorber proposed by Daniel et al.^[22]; (e) structure diagram and (f) absorption spectra of terahertz metamaterial perfect absorber proposed by Cheng et al.^[23]

Fig. 4. (a) Structure diagram and (b) absorption spectra of simulated experiments of terahertz metamaterial perfect absorber proposed by Wen et al.^[26];(c) structure diagram and (d) absorption spectra of terahertz metamaterial perfect absorber proposed by Shen et al.^[37]

Fig. 5. (a) Structure diagram and (b) absorption spectrum of terahertz metamaterial perfect absorber proposed by He et al.^[49];(c) structure diagram and (d) absorption spectrum of terahertz metamaterial perfect absorber proposed by Li et al.^[55]

Fig. 6. (a) Structure diagram and (b) response absorption spectra under different silicon conductivity conditions of terahertz metamaterial perfect absorber proposed by Xu et al.^[58]; (c) structure diagram and (d) effect of different temperatures on absorption spectrum of terahertz metamaterial perfect absorber proposed by Luo et al.^[62]; (e) structure diagram and (f) absorption spectra of terahertz metamaterial perfect absorber proposed by Zhang et al.^[66]