Multi-band terahertz superabsorbers based on perforated square-patch metamaterials

Area of Science:

• Metamaterials and Nanophotonics
• Terahertz Technology

Background:

• Terahertz (THz) superabsorbers are crucial for applications like sensing and imaging.
• Conventional designs often lack multi-band absorption capabilities or require complex structures.

Purpose of the Study:

• To design and demonstrate a novel multi-band terahertz superabsorber.
• To investigate the role of structural modifications in achieving tunable multi-band absorption.

Main Methods:

• Fabrication of a metallic square patch with a precisely engineered small rectangular hole.
• Numerical simulations and analysis of near-field distributions and absorption spectra.
• Experimental characterization of the superabsorber's performance in the terahertz range.

Main Results:

• Achieved >95% absorption across three distinct resonant bands in the terahertz spectrum.
• Demonstrated that the rectangular hole introduces new resonance modes for multi-band absorption.
• Showcased tunability to dual- or quad-band absorption by altering the hole's parameters.

Conclusions:

• The proposed terahertz superabsorber design enables efficient multi-band absorption.
• The engineered rectangular hole is key to controlling near-field interactions and achieving desired absorption characteristics.
• This work offers a promising platform for advanced terahertz devices and applications.