Polarization-Dependent, Frequency-Selective THz Stereometamaterial Perfect Absorber

We present design, fabrication, and characterization of THz stereometamaterial perfect absorber devices. Stereometamaterials consist of a three-dimensional lattice of meta-atoms, which exhibits distinct optical properties depending on the spatial arrangement of the meta-atoms in the unit cell. Integrated into a perfect absorber structure, the absorption and reflection properties of such devices at resonant frequencies reveal unique characteristics that are controlled by the polarization of the incident wave. Because of the break in reflection symmetry, such devices act as polarization-dependent passive switches, with the frequency response of a single band or a dual band absorber. The observed behavior is interpreted in terms of dipole-dipole interaction between the dipoles of the meta-atoms and their mirror images with respect to the metal backplane.