Ultra‐Broadband Polarization‐Independent Terahertz Absorber Based on All‐Dielectric GaN Metamaterials

In this article, an ultra‐wideband wide‐angle absorber based on all dielectric gallium arsenide (GaN) is proposed. The proposed absorber comprises a all dielectric square GaN structure and a GaN substrate. Numerical simulation results demonstrate that the proposed absorber achieves over 90% ultra‐wideband absorption in the range of 0.26–1.7 THz, with a relative bandwidth of 146.9%. The ultra‐broadband absorption property of the proposed absorber is further validated by an equivalent circuit model, which agrees well with the full‐wave numerical simulation results obtained using the finite element method. The simulated electromagnetic field distribution indicates that ultra‐wideband absorption primarily originates from the excitation of Fabry–Perot interference modes and electromagnetic resonance. The proposed absorber exhibits wide‐angle incidence properties and polarization insensitivity in both transverse electric and transverse magnetic modes. Thus, the proposed GaN ultra‐wideband terahertz absorber holds significant potential for applications in fields such as imaging technology and biomedicine.