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Based on the phase transition of vanadium dioxide(VO), an ultra-broadband tunable terahertz metamaterial absorber is proposed. The absorber consists of bilayer VO square ring arrays with different sizes, which are completely wrapped in Topas and placed on gold substrate. The simulation results show that the absorption greater than 90% has frequencies ranging from 1.63 THz to 12.39 THz, which provides an absorption frequency bandwidth of 10.76 THz, and a relative bandwidth of 153.5%. By changing the electrical conductivity of VO, the absorption intensity can be dynamically adjusted between 4.4% and 99.9%. The physical mechanism of complete absorption is elucidated by the impedance matching theory and field distribution. The proposed absorber has demonstrated its properties of polarization insensitivity and wide-angle absorption, and therefore has a variety of application prospects in the terahertz range, such as stealth, modulation, and sensing.
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http://dx.doi.org/10.3390/mi13050669 | DOI Listing |
BaGaGeSe (BGGSe) is a newly developed long-wavelength infrared (LWIR) nonlinear material that exhibits unique advantages in broadband infrared generation, attributed to its wide transmission range, large nonlinear coefficient, high laser damage threshold, and low dispersion property. Here, we systematically investigate the optimal intra-pulse difference-frequency generation process in BGGSe for an ultra-broadband LWIR output, by employing a tunable optical parametric amplifier as driving sources at the wavelengths of 2.0, 2.
View Article and Find Full Text PDFNanoscale Horiz
August 2025
School of Mathematics and Science, Southwest University of Science and Technology, Mianyang 621010, China.
Terahertz (THz) absorbers with ultra-broadband and ultra-narrowband absorption capabilities are crucial for integrated and efficient terahertz modulation. This study proposes a dual-mode tunable terahertz absorber based on the phase transition characteristics of vanadium dioxide (VO), enabling dynamic switching between narrowband and broadband absorption through its insulating-to-metallic transition. In the insulating state, the excitation of quasi-bound states in the continuum (Q-BIC) resonance geometric parameter modulation of silicon pillars is investigated, with its physical mechanism elucidated impedance matching theory and multipole analysis.
View Article and Find Full Text PDFMater Horiz
August 2025
Intelligent Materials and Systems Laboratory, Institute of Technology, University of Tartu, Nooruse 1, Tartu 50411, Estonia.
The increasing global concern over low-frequency noise pollution necessitates innovative solutions capable of effective acoustic attenuation across varying environments. However, conventional acoustic metamaterials, characterized by fixed geometries, typically provide limited flexibility in adjusting the functional frequency range once constructed. This study revisited the classic acoustic metamaterial configurations and proposed two novel tunable acoustic absorbing structures through a strategic integration with high-performance photo-active polymer actuators.
View Article and Find Full Text PDFNanomaterials (Basel)
August 2025
Mechanical and Electronic Engineering College, Shandong Agricultural University, Tai'an 271018, China.
The growing demand for low-frequency, broadband vibration and noise suppression technologies in next-generation mechanical equipment has become increasingly urgent. Effective negative mass locally resonant structures represent one of the most paradigmatic classes of acoustic metamaterials. Their unique elastic wave bandgaps enable efficient suppression of low-frequency vibrations, while inherent nonlinear effects provide significant potential for the design and tunability of these bandgaps.
View Article and Find Full Text PDFDalton Trans
September 2025
Department of Physics and Electronic Engineering, Jinzhong University, Jinzhong 030619, China.
To solve the problems of single absorption function and the complex structure of terahertz absorbers, this study proposes a terahertz (THz) absorber based on vanadium dioxide (VO) driven by electric dipole resonance, which can achieve wideband and narrowband absorption conversion. Simulation results indicate that in the narrowband absorption mode, two narrowband absorption peaks were observed at 14.6 THz and 16.
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