Ultra-flexible polarization-insensitive multiband terahertz metamaterial absorber.

A thin-flexible and polarization-insensitive multiband terahertz metamaterial absorber (MMA) has been investigated. Each unit cell of the MMA consists of two metallic structures, which include the top metal resonator ring and the bottom metal ground plane, separated by a thin-flexible dielectric spacer. Finite element simulation indicates that this MMA has three high absorption peaks in the terahertz region, with absorptivities of 89% at 0.72 THz, 98% at 1.4 THz, and 85% at 2.3 THz. However, because of its rotationally symmetric structure, this MMA is polarization-insensitive and can perform very well at a wide range of incident angles, namely, 30° for transverse electric waves and 40° for transverse magnetic waves. The thin-flexible device structure and good performance shows that this MMA is very promising to disguise objects and make them less detectable to radar in the terahertz region.