Actively Tunable "Single Peak/Broadband" Absorbent, Highly Sensitive Terahertz Smart Device Based on VO2

Micromachines (Basel). 2024 Jan 30;15(2):208. doi: 10.3390/mi15020208.

Abstract

In recent years, the development of terahertz (THz) technology has attracted significant attention. Various tunable devices for THz waves (0.1 THz-10 THz) have been proposed, including devices that modulate the amplitude, polarization, phase, and absorption. Traditional metal materials are often faced with the problem of non-adjustment, so the designed terahertz devices play a single role and do not have multiple uses, which greatly limits their development. As an excellent phase change material, VO2's properties can be transformed by external temperature stimulation, which provides new inspiration for the development of terahertz devices. To address these issues, this study innovatively combines metamaterials with phase change materials, leveraging their design flexibility and temperature-induced phase transition characteristics. We have designed a THz intelligent absorber that not only enables flexible switching between multiple functionalities but also achieves precise performance tuning through temperature stimulation. Furthermore, we have taken into consideration factors such as the polarization mode, environmental temperature, structural parameters, and incident angle, ensuring the device's process tolerance and environmental adaptability. Additionally, by exploiting the principle of localized surface plasmon resonance (LSPR) accompanied by local field enhancement, we have monitored and analyzed the resonant process through electric field characterization. In summary, the innovative approach and superior performance of this structure provide broader insights and methods for THz device design, contributing to its theoretical research value. Moreover, the proposed absorber holds potential for practical applications in electromagnetic invisibility, shielding, modulation, and detection scenarios.

Keywords: heat regulation; local surface plasmon resonance; metamaterial; terahertz; vanadium dioxide.

Grants and funding

The authors are grateful to the support from the Innovative Research Team in Science and Technology at Fujian Province University (IRTSTFJ), the National Natural Science Foundation of China (52102158), the Fujian Provincial Department of Science and Technology (2021H6011, 2023H6037), the Fujian Foreign Cooperation Science and Technology Program (2023I0022), the Quanzhou high level Talents Innovation and Entrepreneurship Project (2023C012R), the Quanzhou Science and Technology Plan Project (2021N052), and the College Student Innovation Training Program Project (S202310399025).