Abstract Controlling the polarization state of terahertz waves, especially their dynamical manipulation, is highly demanded due to the increasing development of practical devices and application systems. Here, we present a terahertz dynamically tunable broadband metamaterial polarization rotator composed of two metal gratings and two orthogonal graphene grating structures as well as the dielectric spacers. By applying different bias voltages to adjust the Fermi energy of graphene, this rotator can conveniently rotate the polarization direction of the linearly polarized incident light by any desired angle among a wide range from 20° to 70° in transmission mode. Moreover, it can operate in a high efficiency, wide bandwidth, and wide angle of incidence tolerance and subwavelength thickness of approximately one-fifth of the central wavelength. Therefore, this work could offer a new platform for exploring dynamically tunable terahertz polarized devices with graphene materials, and have potential applications in various areas, such as wireless communication and terahertz imaging.

中文翻译：

---

基于石墨烯超材料的太赫兹频率可调谐宽带偏振旋转器

摘要 随着实用设备和应用系统的不断发展，对太赫兹波偏振态的控制，尤其是对太赫兹波的动力学控制提出了很高的要求。在这里，我们提出了一种太赫兹动态可调宽带超材料偏振旋转器，由两个金属光栅和两个正交石墨烯光栅结构以及介电间隔物组成。通过施加不同的偏置电压来调整石墨烯的费米能量，该旋转器可以方便地将线偏振入射光的偏振方向旋转20°到70°的大范围内的任意角度。此外，它可以在高效率、宽带宽和宽入射角容差下工作，亚波长厚度约为中心波长的五分之一。