Wang Famei, Hou Liping, Xu Hanlin, Zhang Zhe, Guo Xiaoyang, Lin Qingdian, Yu Jun, Zhou Cangtao, Bao Xu, Yi Zao
Opt Express. 2025 Jun 30;33(13):28627-28639. doi: 10.1364/OE.563708.
Terahertz waves possess unique electromagnetic properties, such as penetration, high capacity, and non-destructive testing capabilities, making the study of their absorption characteristics highly significant. Building on previous narrowband and broadband research, this paper introduces an absorber capable of switching between narrowband and broadband modes. This absorber leverages the tunability of graphene and the phase transition properties of vanadium dioxide (VO) to achieve adjustable and switchable absorption characteristics. When VO is in its insulating state, the absorption spectrum exhibits dual narrowband absorption with an absorption rate approaching 100%. As the temperature increases, VO transitions to a conductive state, resulting in ultra-wideband absorption with a bandwidth of 2.24 THz. Research has shown that the broadband mode is robust with respect to relaxation time and the thickness of VO (within a certain range). The broadband mode is also insensitive to the angle of incidence. The narrow-to-wideband switching absorber demonstrated in this paper offers new insights for research in related fields.
太赫兹波具有独特的电磁特性，如穿透性、高容量和无损检测能力，这使得对其吸收特性的研究具有重要意义。基于以往的窄带和宽带研究，本文介绍了一种能够在窄带和宽带模式之间切换的吸收器。该吸收器利用石墨烯的可调性和二氧化钒（VO）的相变特性来实现可调节和可切换的吸收特性。当VO处于绝缘状态时，吸收光谱呈现出双窄带吸收，吸收率接近100%。随着温度升高，VO转变为导电状态，从而产生带宽为2.24太赫兹的超宽带吸收。研究表明，宽带模式在弛豫时间和VO的厚度（在一定范围内）方面具有鲁棒性。宽带模式对入射角也不敏感。本文展示的窄带到宽带切换吸收器为相关领域的研究提供了新的见解。
