温度电压双可控宽带太赫兹极化转换/吸收超表面

Temperature-Voltage Bi-Controllable Broadband Terahertz Polarization Conversion/Absorption Metasurface

提出了一种基于二氧化钒(VO_(2))和石墨烯材料的温度电压双可控宽带极化转换/吸收超表面。通过调控超表面中VO_(2)和石墨烯的电导特性能够实现对极化转换和吸收功能的控制。结果显示:当VO_(2)处于金属态且石墨烯处于绝缘态时,超表面工作在宽带极化转换模式,在1.57~2.49 THz范围内可实现线极化转换功能;当VO_(2)处于绝缘态且石墨烯处于金属态时,超表面的工作状态切换为吸收模式,在1.56~2.99 THz范围内的吸收率均大于90%;极化转换和吸收性能可以分别通过控制VO_(2)的温度和石墨烯的偏置电压来调控。此外,通过本征模、阻抗匹配理论和电流磁场分布解释了该超表面的工作原理,并讨论了其工作性能在不同结构参数和入射角度下的稳定性。

A temperature-voltage bi-controllable broadband polarization conversion/absorption metasurface based on vanadium dioxide(VO_(2))and graphene is proposed.The control of the polarization conversion and absorption function can be realized by regulating the conductance properties of VO_(2) and graphene in the metasurface.The results show that when VO_(2) is in metal state and graphene is in insulating state,the metasurface operates in the broadband polarization conversion mode,achieving linear polarization conversion in the range of 1.57--2.49 THz.When VO_(2) is in insulating state and graphene is in metal state,the operation mode of the metasurface is switched to the absorption mode,and the absorptivity reaches 90%in the range of 1.56--2.99 THz.The polarization conversion and absorption performance can be controlled by regulating the temperature of VO_(2) and the bias voltage of graphene,respectively.Furthermore,the working principle of the metasurface is explained by eigenmodes,impedance matching theory,and current and magnetic field distributions.The stability of its performance under different structural parameters and incident angles is also discussed.