Broadband NIR absorber based on square lattice arrangement in metallic and dielectric state VO2

In this Letter, we propose a broadband near-infrared (NIR) absorber based on the phase transition material VO2. By designing different arrangements of the VO2 square lattice at high and low temperatures on fused silica substrates, the absorption rate reaches more than 90% in the entire 1.4-2.4 mu m range. Using a finite-difference time-domain simulation method and thermal field analysis, the results prove that the absorber is polarization-independent and has wide-angle absorption for incident angles of 0 degrees-70 degrees. The proposed absorber has a smoother absorption curve and is superior in performance, and it has many application prospects in remote sensing geology.