Design and analysis of a quad-band perfect metamaterial absorber with enhanced sensing capabilities in the terahertz regime

Abstract This study presents the design and analysis of a Quad-band perfect metamaterial absorber (PMMA) with five distinct absorption peaks, achieving absorption rates consistently above 96%. The absorption performance is thoroughly examined by varying the structural parameters to elucidate the mechanisms underlying the multi-band absorption. Additionally, we investigate the sensing capabilities of the absorber by analyzing its response to changes in the refractive index and thickness of the analyte. Sensitivity and figure of Merit (FOM) are utilized to evaluate the sensing performance. The sensor demonstrates refractive index and thickness sensitivities of 1.5 THz RIU −1 and 0.5 THz RIU −1 , respectively, with corresponding FOMs of 97.424 and 91.633. These results surpass those of prior terahertz regime designs, highlighting the superior sensing capabilities of the proposed absorber. The proposed design is promising for sensing, filtering, and stealth technology applications.