Fig. 4: Experimental demonstration of an incident-angle-selective meta-absorber.

a Schematic of the radiation pattern of an MIM meta-atom excited by TE-polarized light. b SEM image of the fabricated sample. c \(\Gamma _i(\theta )\) and \(\Gamma _r(\theta )\) relations of the metasurface retrieved from FEM simulations, compared with the \(\Gamma _r(\theta )\) relation calculated by the analytical expression Eq. (5). d Measured and simulated reflectance spectra of the sample illuminated by TE-polarized light at different incident angles. e Measured and simulated peak absorbance and quality factor of the resonance for the metasurface illuminated by TE-polarized light at different incident angles. Here, silver (Ag) is used as a metallic material. The geometrical parameters of the meta-device are P_x = 120 nm, P_y = 300 nm, L_x = 50 nm, L_y = 200 nm, t = 30 nm, t_s = 50 nm and t_m = 150 nm