Active Modulation of Absorption Properties of a Heat-Sensitive Metasurface Based on Vanadium Dioxide

Metasurface-based devices are utilized to achieve high absorption in the determined target frequency band and applied in sensing. The dielectric properties of the vanadium dioxide (VO2) can be modulated by temperature. The development of metasurface devices based on the tunability of VO2 has attracted a lot of attention. In this work, the coupling effect between bright modes results in an absorption peak at 7.71THz at room temperature. This absorption peak is enhanced through optimizing parameters P or D in experiments. As the parameter P increases, the absorption peak is strengthened and moved to high frequencies. Conversely, when the parameter D is increased, this absorption peak is moved to low frequencies. An LC mode is suggested to reveal the influence of structural parameters (P, D) on the absorption properties. Two measured FOM (19.4, and 29) are obtained based on liquid sensing at room temperature. Since the resonance property of the VO2 layer is temperature reversible, the absorption performance of the metasurface is repeatable in the heating and cooling process. In the final experiments, the absorption peak is controlled in the heating and cooling process. Such a metasurface can be applied in liquid sensing and temperature sensing.