Shandong Technology Center of Nanodevices and Integration, School of Integrated Circuits, Shandong University, Jinan 250100, China
Ke Li
Key Laboratory for Physical Electronics and Devices of the Ministry of Education & Shaanxi Key Laboratory of Information Photonic Technique, School of Electronic Science and Engineering, Faculty of Electronic and Information Engineering, Xi’an Jiaotong University, Xi’an 710049, China
Yiming Wang
Shandong Technology Center of Nanodevices and Integration, School of Integrated Circuits, Shandong University, Jinan 250100, China
Zihao Zhang
Shandong Technology Center of Nanodevices and Integration, School of Integrated Circuits, Shandong University, Jinan 250100, China
Yanpeng Shi
Shandong Technology Center of Nanodevices and Integration, School of Integrated Circuits, Shandong University, Jinan 250100, China
Aimin Song
Institute of Nanoscience and Applications, Southern University of Science and Technology, Shenzhen 518055, China
Yifei Zhang
Shandong Technology Center of Nanodevices and Integration, School of Integrated Circuits, Shandong University, Jinan 250100, China
Tightly coupled meta-atoms (TCMAs) are densely packed metamaterials with unnatural refractive indexes. Actively modulated TCMAs with tunable optical properties have found many applications in beam shaping, holography, and enhanced light–matter interactions. Typically, TCMAs are studied in the classic Bloch theory. Here, tightly coupled H-shaped meta-atoms are proposed with an ultra-high permittivity of ~6000, and their active modulation with graphene is designed by using the tightly coupled dipole array (TCDA) theory. The H-shaped meta-atoms are used as dipole arms, and the graphene strips function as the dipole loads. By tuning the chemical potential of graphene, the resonant amplitude, frequency, and permittivity are dynamically modulated. The simulations indicate that the real and imaginary parts of permittivity change from 6854 to 1522 and from 7356 to 2870, respectively. The experimental validation demonstrates a modulation depth of 11.6% in the resonant frequency, i.e., from 219.4 to 195 GHz, and a substantial 52.5% modulation depth in transmittance under a bias voltage of less than 1.5 V.
