Fig. 1. Metamaterial terahertz multi-frequency absorber with square symmetric structure. (a) Three-dimensional structure diagram; (b) front view and structural dimensions

Fig. 2. Simulation results of a square symmetric metamaterial absorber

Fig. 3. Current distribution diagram on terahertz absorber surface in transverse magnetic polarization state

Fig. 4. Comparison of absorption curves of different cross bond widths g

Fig. 5. Comparison of absorption curves of different cross bond lengths k

Fig. 6. Comparison of absorption curves of different corner lengths a

Fig. 7. Comparison of absorption curves of different edge angle widths d

Fig. 8. Comparison of absorption curves of different margins L

Fig. 9. Comparison of absorption curves of different substrate thicknesses t

Fig. 10. Comparison of absorption curves for different period lengths W

Fig. 11. Comparison of absorption curves of different incident angles