Ren Yi, Zhou Tianle, Jiang Chun, Tang Bin
Opt Express. 2021 Mar 1;29(5):7666-7679. doi: 10.1364/OE.418273.
In this paper, we propose a switchable bi-functional metamaterial device based on a hybrid gold-vanadium dioxide (VO) nanostructure. Utilizing the property of a metal-to-insulator transition in VO, perfect absorption and asymmetric transmission (AT) can be thermally switched for circularly polarized light in the near-infrared region. When VO is in the metallic state, the designed metamaterial device behaves as a chiral-selective plasmonic perfect absorber, which can result in an optical circular dichroism (CD) response with a maximum value ∼ 0.7. When VO is in the insulating state, the proposed metamaterial device exhibits a dual-band AT effect. The combined hybridization model and electromagnetic field distributions are presented to explain the physical mechanisms of chiral-selective perfect absorption and AT effect, respectively. The influences of structure parameters on CD response and AT effect are also discussed. Moreover, the proposed switchable bi-functional device is robust against the incident angle for obtaining perfect absorption and strong CD response as well as the AT effect. Our work may provide a promising path for the development of multifunctional optoelectronic devices, such as thermal emitters, optical modulators, CD spectroscopy, optical isolator, etc.
在本文中，我们提出了一种基于金 - 二氧化钒（VO₂）混合纳米结构的可切换双功能超材料器件。利用VO₂中金属 - 绝缘体转变的特性，对于近红外区域的圆偏振光，完美吸收和非对称传输（AT）可以通过热切换实现。当VO₂处于金属态时，所设计的超材料器件表现为手性选择性等离子体完美吸收体，可产生最大值约为0.7的光学圆二色性（CD）响应。当VO₂处于绝缘态时，所提出的超材料器件呈现出双波段AT效应。分别给出了组合杂化模型和电磁场分布，以解释手性选择性完美吸收和AT效应的物理机制。还讨论了结构参数对CD响应和AT效应的影响。此外，所提出的可切换双功能器件在获得完美吸收、强CD响应以及AT效应方面对入射角具有鲁棒性。我们的工作可能为多功能光电器件的发展提供一条有前景的途径，如热发射器、光调制器、CD光谱仪、光隔离器等。
