Reduced Cell Size Metamaterial Based Wideband Infrared Absorber

A novel design of metamaterial (MTM) based absorber with reduced cell size is proposed in this paper. The absorber is designed to operate in the mid infrared (IR) regime using gold nano-pillar inclusions embedded in a dielectric spacer. The absorption band can be controlled by adjusting the nano-pillar’s properties. Numerical simulations have been conducted to investigate the effect of these inclusions on the absorber performance. Moreover, a wideband absorber is designed by combining four different sized resonant elements within the unit cell. The absorber shows enhanced characteristics such as large bandwidth, small cell size to wavelength ratio and high absorption level for wide range of incident angles for different wave polarizations. The achieved bandwidth is around 60% with normalized absorption percentage of 80% over the band 5.2-9.8μm, and cell size ratio of 0.34λ. Keywords— Metamaterials, Multi-sized absorber, Nano-pillar inclusions, Subwavelength structures, Wideband IR absorber.