Multiband Terahertz Metamaterial Absorber Based on Multipolar Plasmonic Resonances

Terahertz metamaterial absorbers (MMA) have found wide scope of research prospective, remarkably in the development of multiband absorbers. Considerable applications are established using these multiband absorbers in THz imaging, wireless communication and bolometric detectors. The MMA was built on a GaAs substrate of 30 µm thickness and the hexagonal metallic pattern was etched out on a gold layer of 0.4 µm thickness on the top surface. The underlying ground layer is metallic backed. This design realizes the multiband (9-bands) of absorption in the spectral region from 0.56 to 0.92 THz. The multiband absorption mechanism of the absorber was examined by electric field dispersion analysis and impedance matching concept. From the established results, the absorber exhibits nine bands within a narrow frequency range and secures promising applications in hyperspectral imaging, clinical sensing and detection.