Three-dimensional metamaterial for reconfigurable multi-band electromagnetically induced transparency based on VO₂

Conventional 2D planar metamaterials struggle to achieve multi-band electromagnetically induced transparency (EIT) effects due to structural constraints. This paper proposes what we believe to be a novel three-dimensional (3D) metamaterial consisting of a vertical split-ring resonator with vanadium dioxide (VO 2 ) islands at the openings. Based on VO 2 ’s reversible phase transition capabilities, the designed metamaterial has excellent reconfigurability for multi-band EIT effects. When the surface temperature is at room temperature, VO 2 exhibits an insulating state. The near-field coupling between bright and dark modes leads to a triple-band EIT effect at 1.72, 1.82, and 1.91 THz, characterized by multi-band, low-loss, and narrowband filtering. In contrast, when the temperature exceeds 68°C, VO 2 transitions to its metallic state, resulting in a single transmission window with favorable slow light characteristics. Compared to traditional EIT metamaterials, our work realizes multi-band modulation and switchable operating modes, enhancing flexibility and adaptability. The excellent performance indicates its suitability for various applications, including multi-channel sensors, switchable absorptions, enhancing coupling and slow light devices, etc.