Active tunable bidirectional terahertz absorber based on dual-metasurface hybrid liquid-crystal metamaterials
Year: 2026
Type: article
Abstract: Terahertz (THz) metamaterial absorbers are widely studied for communication, sensing, and stealth applications. Most conventional designs use a single metasurface with a metallic ground plane that enhances absorption but blocks reverse coupling, leading to unidirectional response and limiting dual-sided or reconfigurable THz applications. Here, we propose an actively tunable bidirectional THz absorber based on a dual-metasurface architecture integrating hybrid liquid-crystal (LC) metamaterials. The device comprises two orthogonally rotated quarter-ring gold resonator layers separated by a voltage-controlled LC interlayer, which enables bidirectional absorption without the need for a metallic backplane. Numerical simulations reveal peak absorption efficiencies of 96.8% (forward) and 97.3% (backward) at 1.02 THz. By exploiting the electrically induced birefringence of the LC layer, the resonance frequency is continuously tuned from 1.02 THz to 1.18 THz under external bias. The electric-field analysis confirms that the bidirectional response arises from plasmonic coupling between the two metasurfaces separated by the LC spacer. The proposed design provides a compact, reconfigurable platform for dynamically tunable THz absorbers, offering new possibilities for two-sided sensing, adaptive communication, and stealth technologies.
Source: Applied Optics
DOI: 10.1364/ao.589360
Authors: Wen-Long Ji, Huan Liu, Jia-Jian Sun, Jing Ma, Ya-Xian Fan, Zhi-Yong Tao
Institution: Guilin University of Electronic Technology
Language: English
Field: Materials Science
Domain: Physical Sciences
Open Access status: green
OpenAlex ID: W7151502849