A broadband terahertz absorber using multi-layer stacked bars

• DOI: 10.1063/1.4918289
• Publication Date: 2015-04-13T17:09:24Z
• Authors: Shuo Liu; Haibing Chen; Tie Jun Cui
• Keywords: 02 engineering and technology; 0210 nano-technology; 7. Clean energy

We present the simulation, implementation, and measurement of a broadband terahertz (THz) metamaterial absorber. By stacking 12 metallic bars of varying lengths on three polyimide layers with equal spacing, a broadband absorption spectrum is formed through merging multiple successive resonance peaks. The measured total absorption exceeds 95% from 0.81 to 1.32 THz at the normal incidence and the full width at half maximum is 64% (from 0.76 to 1.48 THz). The absorption decreases with fluctuations as the incident angle increases but remains above 62% even at the incident angle of 40°. The physical explanation to the absorption mechanism is presented and verified by a 9-bar example, which exhibits narrower absorption bandwidth. It is also experimentally demonstrated that the proposed structure is robust against misalignment of each metallic layer.