School of Electronic and Electrical Engineering, Wuhan Textile University, Wuhan, Hubei, 430073, China.
State Key Laboratory for Hubei New Textile Materials and Advanced Processing Technology, Wuhan Textile University, Wuhan, 430020, China.
Sci Rep. 2018 Jan 9;8(1):189. doi: 10.1038/s41598-017-18472-x.
Compared with natural materials, chiral metamaterials have been demonstrated with orders of magnitude stronger chiroptical response, which provides the basis for applications such as ultracompact polarization components and plasmonic-enhanced biosensing. Terahertz chiral metamaterials that allow dynamic polarization control of terahertz waves are of great practical interest, but remain extremely rare. Here, we show that hybrid metamaterials integrated with vanadium dioxide (VO) exhibiting phase transition can enable dynamically tunable chiroptical responses at terahertz frequencies. In particular, a circular dichroism of ~40° and a maximum polarization rotation of ~200°/λ are observed around 0.7 THz. Furthermore, our study also reveals that the chiroptical response from the proposed metamaterials is strongly dependent on the phase transition of VO, leading to actively controllable polarization states of the transmitted terahertz waves. This work paves the way for the development of terahertz metadevices capable of enabling active polarization manipulation.
与天然材料相比，手性超材料具有数量级更强的手性光学响应，这为超紧凑偏振元件和等离子体增强生物传感等应用提供了基础。允许动态控制太赫兹波偏振的太赫兹手性超材料具有很大的实际意义，但仍然极为罕见。在这里，我们展示了与表现出相变的二氧化钒 (VO) 集成的混合超材料可实现太赫兹频率下动态可调的手性光学响应。具体而言，在 0.7 THz 左右观察到约 40°的圆二色性和最大约 200°/λ的偏振旋转。此外，我们的研究还表明，所提出的超材料的手性光学响应强烈依赖于 VO 的相变，从而导致传输的太赫兹波的偏振状态可主动控制。这项工作为开发能够实现主动偏振操控的太赫兹 metamaterials 铺平了道路。
