Simplified Design for Broadband and Polarization-Insensitive Terahertz Metamaterial Absorber

Broadband perfect light absorbers have application promising in many areas. However, current design concept of broadband absorbers using the configurations of super-unit coplanar or stacked has shortcomings of complexity in design and challenge in fabrication. We here only employ a patch resonator without using the complex structures of coplanar or stacked to achieve the broadband and polarization-insensitive terahertz light absorber. Larger than 80% absorption can cover a continuous range of 2.83 THz, and its relative bandwidth can reach 77.64%. The combination of fundamental mode of patch resonator and two different coupling intensities of localized resonance and surface propagation mode results in the broadband absorption, and field distributions are given to reveal its physical mechanism. Furthermore, the design can offer a deal of freedom for widening the bandwidth of the device through some parameters redesigning.