Triple Band Polarisation Sensitive Metamaterial Absorber for Terahertz Applications

In this work, we propose a novel-shaped metamaterial absorber (MMA) for terahertz (THz) applications. The proposed MMA comprises of metallic layers separated by gallium arsenide (GaAs) substrate demonstrating three absorption peaks at 1.71, 3.16 and 4.89 THz with absorptivity of 99.4, 99.6 and 90.5%, respectively. The normalized impedance, constitutive electromagnetic (EM) parameters, surface current and electric field distributions are analyzed for better understanding of absorption mechanism. The absorption with different incident and polarization angles is also analyzed. The proposed absorber is ultra-compact (0.058λ) and ultra-thin (0.028λ) at the lowest frequency of operation, hence, can be utilized for potential applications including sensing and imaging.