School of Science, Zhejiang University of Science and Technology, Hangzhou, China.
College of Electrical Engineering, Anhui Polytechnic University, Wuhu, 241000, China.
Phys Chem Chem Phys. 2022 Dec 21;25(1):778-787. doi: 10.1039/d2cp03620g.
In this work, we designed a terahertz absorber based on vanadium dioxide (VO) with tunable and ultra-broadband characteristics. This absorber is composed of four identical synthetic VO patterns, a dielectric layer and a metal reflector layer from top to bottom. The designed absorber is found to achieve essentially total reflection when VO is in the insulated state. The designed absorber has an absorption bandwidth of over 90% absorptance up to 7.7 THz in the frequency range of 5.36-13.06 THz when VO is in the metallic state. By adjusting the conductivity of VO, the absorber realizes near-perfect modulation of the amplitude with its absorbance dynamically tuned from 4.31% to 100%. The operating principle of the ultra-broadband absorber is interpreted by wave interference theory, impedance matching theory, and electric field analysis. Compared to previously reported terahertz absorbers, the designed absorber offers significant improvements in the absorption broadband, and it also has many advantages such as a simple structure, polarization insensitivity, and a flexible incident angle. These tunable ultra-broadband terahertz absorbers hold great promise in the fields of photochemical energy absorption, thermal emitters, and stealth devices.
在这项工作中，我们设计了一种基于二氧化钒（VO）的太赫兹吸收体，具有可调谐和超宽带特性。该吸收体由四个相同的合成 VO 图案、一个介电层和一个金属反射层从上到下组成。当 VO 处于绝缘状态时，设计的吸收体被发现实现了基本上完全的反射。当 VO 处于金属状态时，设计的吸收体在 5.36-13.06 THz 的频率范围内具有超过 90%的吸收带宽，吸收率高达 7.7 THz。通过调整 VO 的电导率，吸收体实现了对振幅的近乎完美调制，其吸收率从 4.31%动态调谐到 100%。超宽带吸收体的工作原理通过波干涉理论、阻抗匹配理论和电场分析来解释。与之前报道的太赫兹吸收体相比，设计的吸收体在吸收宽带方面有了显著的提高，并且具有结构简单、偏振不敏感、入射角灵活等优点。这些可调谐的超宽带太赫兹吸收体在光化学能量吸收、热发射器和隐形器件等领域具有广阔的应用前景。
