Fig. 1. Modularized design of the hybrid plasmonic metasurface for the surface-enhanced infrared absorption (SEIRA) sensor. (A) The effect of the determining factors on the SEIRA sensor properties. (B) The diagram of the hybrid plasmonic metasurface sensor. (C) The optical properties of the metasurface in the near field (electromagnetic field) and far field (spectrum).

Fig. 2. The influence of parameters on the spectral properties of the metasurfaces. (A)–(D) The influence of parameters (the total thickness of the dielectric layer H, the width of grating w, the period P, and the hybrid dielectric layers ASA and SAS) on the radiative damping γ_e and absorptive damping γ_o of the metasurfaces. The colors of the background represent different potential couplings of the metasurface (Red, OC; White, CC; Blue, UC). (E) The influence of parameter space on the resonance frequency of the metasurfaces.

Fig. 3. The influence of parameters on the extinction properties of the metasurfaces. (A) Comparison of the spectral properties in the far field, and the extinction properties of the metasurfaces in the near field. (B)–(F) The influence of parameter space (B, the total thickness of the dielectric layer H; C, the width of grating w; D, the period P; E, F, the hybrid dielectric layers ASA and SAS) on the extinction properties of the metasurfaces. The black dotted lines represent the central frequencies of the resonances.

Fig. 4. The influence of detuning properties of the OC metasurface on the broadband SEIRAS. (A) The enhanced absorptance and magnification of the OC metasurface sensor with detuning. (B) C_sca of the metasurface after OC coupling. (C) C_abs of the metasurface after OC coupling. (D) C_sca/C_abs of the metasurfaces after the OC coupling.

Fig. 5. The influence of OC level of the metasurfaces on the SEIRAS. (A) The absorptance amplification with detuning in different OC metasurfaces. (B)–(E) The extinction properties of the OC system at zero detuning (B, H = 150 nm, γ_e/γ_o = 3.2; C, H = 210 nm, γ_e/γ_o = 5.8; D, H =300 nm, γ_e/γ_o = 11.0; E, H = 450 nm, γ_e/γ_o = 24.3). The red, white, and blue backgrounds represent the OC, CC, and UC states of the metasurfaces, respectively.

Fig. 6. Potential of the hybrid dielectric layer on the signal amplification. (A) The electromagnetic field and amplified absorptance with detuning in the ASA topological metasurfaces. (B)–(D) The extinction properties of the metasurfaces at zero detuning (B, H₁ = 25 nm, γ_e/γ_o = 13.1; C, H₁ = 50 nm, γ_e/γ_o = 14.1; D, H₁ = 150 nm, γ_e/γ_o = 20.3). (E) The variation of the SD C_sca/C_abs in the ASA metasurfaces. (F) The electromagnetic field and the amplified absorptance with detuning in the SAS topological metasurfaces. (G)–(I) The extinction properties of the metasurfaces at zero detuning (G, H₁ = 25 nm, γ_e/γ_o = 22.3; H, H₁ = 50 nm, γ_e/γ_o = 20.3; I, H₁ =150 nm, γ_e/γ_o = 17.3). (J) The variation of the SD C_sca/C_abs in the SAS metasurfaces.