Fig. 1. Schematic diagram of absorber by hybrid integration of the upper and lower parts.

Fig. 2. (a) Schematic of the unit cell of the absorber. (b) The cross-sectional view of the absorber. (c) Top view of the unit cell for the absorber.

Fig. 3. (a) Absorption change with h₁. (b) Absorption change with h₂. (c) Absorption change with h₃. (d) Absorption change with L.

Fig. 4. (a) Absorption change with L when the VO₂ nanocylinder array is prepared on the front illuminated surface. (b) Absorption change with the radius of the VO₂ nanocylinder array r. (c) Absorption change with the height of the VO₂ nanocylinder array h. (d) Absorption change with the structural spacing Δh. (e) Absorption change with the variation of individual cycle size p.

Fig. 5. Calculated absorption spectrum.

Fig. 6. (a) The electric field distribution in XY plane. (b) The magnetic field distribution in XY plane. (c) The electric field distribution in XZ plane. (d) The magnetic field distribution in XZ plane.

Fig. 7. (a) Steady state temperature field distribution of the absorber. (b) Transient temperature change of the absorber. (c) Absorption change with alignment deviation. (d) Absorption change with T1 and T2. (e) Absorption change with ambient temperature T.

Fig. 8. Absorption spectra at different polarization angles.

Fig. 9. (a) Absorption spectra at different incident angles under TE. (b) Absorption spectra at different incident angles under TM.

Table 1. Comparison of works on the broadband absorbers in the NMIR range in recent years.