Polarization controllable THz stereometamaterial absorber

Spatially different arrangements of identical metaatoms in a unit cell bring about distinct properties in stereometamaterials. Integrating the stereometamaterial into a perfect metamaterial absorber, we designed, fabricated, and characterized a device with single or double band absorption responses and an absorption/reflection switching characteristic dependent upon the polarization of the incident THz wave. Two non-concentric Cu rings tightly coupled via a polyimide layer form the stereometamaterial frequency selective surface (FSS). The FSS is placed on another polyimide layer deposited on a Cu backplane. Despite the rotational symmetry of the rings, non-centricity breaks the reflection symmetry of the FSS, leading to a unique interaction between the rings and a Cu backplane. Interaction between dipoles on an FSS and their mirror images due to Cu backplane is studied to gain a better understanding of this device.