Ultrabroad and Wide‐Angle High‐Temperature‐Stability Infrared Metamaterial Absorber Based on All‐Dielectric Silicon Nitride (Si 3 N 4 )

Ultrabroadband absorption across the long‐wave and ultralong‐wave infrared (LWIR/ULWIR) spectrum is essential for applications ranging from thermal imaging to spectroscopy, yet remains a persistent challenge. Herein, a refractory metamaterial absorber (MMA) composed of four vertically tapered silicon nitride (Si 3 N 4 ) rods on a tungsten substrate is proposed. Finite element method (FEM) simulations show that the MMA achieves an absorbance of over 90% from 7.15 to 31.62 μm, with a relative bandwidth of 126.23%. Notably, the absorbance peak of the MMA is up to 99.97%, 97.92%, 98.42%, and 99.96% at 7.653, 9.045, 16.762, and 26.731 μm, respectively. An equivalent circuit model corroborates these results and…

• NN
  National Natural Science Foundation of China

  Award: 52304410
• NK
  National Key Research and Development Program of China

  Award: 2024YFB3714603