Affiliation:
1. Communication University of China
2. Beijing Institute of Electronic System Engineering
Abstract
This study presents a novel, to our knowledge, polarization-insensitive terahertz absorber with an actively adjustable bandwidth. The absorber consists of a vertically stacked three-layer structure with target-shaped resonant layers. Its absorption bandwidth is dynamically controlled, exhibiting ultra-broadband characteristics in the metallic phase. The absorber achieves over 90% absorption from 1.8 to 31.7 THz, with a relative bandwidth of 178%. In the insulating phase, the device transforms into a narrowband absorber, showing a precise absorption peak within the 0 to 20 THz frequency range. Notably, this absorber demonstrates polarization-insensitive and wide-angle absorption properties, making it suitable for different application scenarios. Compared to traditional broadband absorbers, the absorber proposed in this study features an ultra-wide absorption bandwidth and switchable operating modes, enhancing its flexibility and adaptability. The excellent performance of the absorber indicates its suitability for various applications, such as sixth-generation (6G) wireless communication, security detection, imaging, military stealth technology, and energy harvesting.
Funder
Beijing Municipal Natural Science Foundation
Fundamental Research Funds for the Central Universities
National Natural Science Foundation of China