Fig. 1. (a) Schematic of LIG fabrication. (b) Grid graphene THz absorber. (c) Unit cell of the absorber.

Fig. 2. (a) Sample of the LIG absorber. (b) Graphene grid observed under a microscope. (c) Raman spectra of the LIG and PI. (d) SEM image of the LIG. (e) SEM image of the cross section of the LIG.

Fig. 3. (a) Time-domain results of the THz graphene grid absorbers induced by the different laser power ranging from 40% to 80%. (b) Corresponding transmittance spectra, (c) reflectance spectra, and (d) absorption spectra of the absorbers.

Fig. 4. (a) Graphene grid absorbers induced with different laser scanning speeds under a microscope. (b) Corresponding experimental and simulated absorption spectra of the absorbers. (c) Simulated THz near-field distributions of the absorber (W = 300 µm) at a frequency of 0.8 THz, 1 THz, 1.2 THz, and 1.5 THz, respectively.