Qureshi Ubaid Ur Rahman, Basir Shahid, Mallek Fatma, Hamam Habib
Beijing Engineering Research Center for Mixed Reality and Advanced Display, School of Optics and Photonics, Beijing Institute of Technology, Beijing, 100081, China.
School of Engineering and Applied Sciences, ISRA University, Islamabad, Pakistan.
Sci Rep. 2024 Mar 1;14(1):5118. doi: 10.1038/s41598-024-55676-4.
Motivated by the imperative demand for design integration and miniaturization within the terahertz (THz) spectrum, this study presents an innovative solution to the challenges associated with singular functionality, limited application scope, and intricate structures prevalent in conventional metasurfaces. The proposed multifunctional tunable metasurface leverages a hybridized grapheme-metal structure, addressing critical limitations in existing designs. Comprising three distinct layers, namely a graphene-gold resonance layer, a Topas dielectric layer, and a bottom gold film reflective layer, this terahertz metasurface exhibits multifunctionality that is both polarization and incident-angle independent. The metasurface demonstrates a broadband circular dichroism (CD) function when subjected to incident circularly polarized waves. In contrast, under linear incidence, the proposed design achieves functionalities encompassing linear dichroism (LD) and polarization conversion. Remarkably, graphene's chemical potential and the incident light's state can be manipulated to tune each functional aspect's intensity finely. The proposed tunable multifaceted metasurface showcases significant referential importance within the terahertz spectrum, mainly contributing to advancing CD metamirrors, chiral photodetectors, polarization digital imaging systems, and intelligent switches.
受太赫兹（THz）频谱内设计集成和小型化的迫切需求驱动，本研究针对传统超表面中普遍存在的单一功能、有限应用范围和复杂结构等挑战，提出了一种创新解决方案。所提出的多功能可调谐超表面利用了一种石墨烯 - 金属混合结构，解决了现有设计中的关键局限性。这种太赫兹超表面由三个不同的层组成，即石墨烯 - 金共振层、Topas介电层和底部金膜反射层，展现出与偏振和入射角无关的多功能性。当受到入射圆偏振波作用时，该超表面表现出宽带圆二色性（CD）功能。相比之下，在直线入射情况下，所提出的设计实现了包括线性二色性（LD）和偏振转换在内的功能。值得注意的是，可以通过操纵石墨烯的化学势和入射光的状态来精细调节每个功能方面的强度。所提出的可调谐多面超表面在太赫兹频谱内具有重要的参考价值，主要有助于推进CD超镜、手性光电探测器、偏振数字成像系统和智能开关的发展。
