Abstract
A simple design of an ultrathin six-band polarization-insensitive terahertz perfect metamaterial absorber (PMMA), composed of a metal cross-cave patch resonator (CCPR) placed over a ground plane, was proposed and investigated numerically. The numerical simulation results demonstrate that the average absorption peaks are up to 95% at six resonance frequencies. Owing to the ultra-narrow band resonance absorption of the structure, the designed PMMA also exhibits a higher Q factor (>65). In addition, the absorption properties can be kept stable for both normal incident transverse magnetic (TM) and transverse electric (TE) waves. The physical mechanism behind the observed high-level absorption is illustrated by the electric and power loss density distributions. The perfect absorption originates mainly from the higher-order multipolar plasmon resonance of the structure, which differs sharply from most previous studies of PMMAs. Furthermore, the resonance absorption properties of the PMMA can be modified and adjusted easily by varying the geometric parameters of the unit cell.
Highlights
It exhibited a frequency selectivity of the six-band perfect metamaterial absorber (PMMA), since the bandwidth of perfect absorption is very narrow and the off-resonance absorption is very small (A(ω) < 5%)
We present an ultrathin six-peak PMMA based on a metallic square cross-cave patch structure placed over a ground plane separated by a dielectric substrate
The high absorption level of the designed PMMA can be kept almost unchanged with different polarization angles for both transverse electric (TE) and transverse magnetic (TM) waves under normal incidence
Summary
Since the perfect metamaterial absorber (PMMA) concept was first proposed and demonstrated experimentally by Landy et al [1], it has become a hot research topic of science and technology. There are two design strategies to achieve multi-band absorption or to extend the absorption bandwidth for PMMAs. One approach is to combine multiple sub-units within a coplanar super-unit resonant structure [6,7,8], and another method is to construct an alternating multiple patterned metallic structure and dielectric layers with different geometric parameters stacked vertically [28,29,30,31,32]. Wang et al proposed a PMMA based on a single patched structure, which can achieve a dual-band and triple-band absorption originating from the fundamental resonance and high-order responses by appropriate geometric parameters designs [36]. Such a simple and effective design may provide some potential applications in biological sensing, material detection, thermal imaging, and communications at terahertz regions
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
