Development of frequency-tunable multiple-band terahertz absorber based on control of polarization angles.

Controlling and tuning the spectral absorption response of metamaterial absorbers fabricated by arranging a set of resonators in a regular array is challenging. Polarization tunable multi-band terahertz resonant absorbers were developed using anisotropic microstructure arrays. The unit cell consisted of four pairs of H-shaped resonators of different sizes and a metallic ground plane separated by a dielectric layer. Discrete operating frequency shifts and dynamic amplitude tuning were observed by changing the polarization angle. The effect of the polarization angle on the absorption amplitude was evaluated. This work provides a concise approach to realize tunable absorption characteristics, which can be applied in sensors, detectors, and switches.