Fig. 1. Schematics of proposed absorber structure. (a) Unit structure; (b) array structure

Fig. 2. Equivalent circuit model of resonator unit of proposed structure

Fig. 3. Dynamically switchable absorption spectra of absorber excited by laser with different wavelengths and absorption spectra at three dual-frequency absorption states. (a) Absorption spectra excited by 800 nm laser; (b) absorption spectra excited by 1500 nm laser; (c)(d)(e) absorption spectra at three dual-frequency absorption states

Fig. 4. Relative impedances of absorber at different excitation states. (a) No laser pumping; (b) 1550 nm laser pumping; (c) 800 nm laser pumping

Fig. 5. Current distributions at different resonance frequencies. (a) 0.987 THz; (b) 1.767 THz; (c) 0.717 THz; (d) 1.444 THz

Fig. 6. Absorption characteristics of proposed absorber for normal incident TE and TM waves. (a)(b) No laser pumping; (c)(d) 800 nm laser pumping; (e)(f) 1550 nm laser pumping

Fig. 7. Influence of main size parameters of unit structure on absorption characteristics. (a) Side length of square ring L₁; (b) width of square ring w₁; (c) length of outer wire L₂; (d) width of outer wire w₂