TY - JOUR
T1 - Graphene-Tuned, Tightly Coupled Hybrid Plasmonic Meta-Atoms
AU - Chen, Kai
AU - Li, Ke
AU - Wang, Yiming
AU - Zhang, Zihao
AU - Shi, Yanpeng
AU - Song, Aimin
AU - Zhang, Yifei
N1 - Publisher Copyright:
© 2024 by the authors.
PY - 2024/4/19
Y1 - 2024/4/19
N2 - 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.
AB - 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.
KW - graphene
KW - plasmonic
KW - terahertz
KW - tightly coupled antenna array
KW - tightly coupled meta-atom
UR - http://www.scopus.com/inward/record.url?scp=85191716176&partnerID=8YFLogxK
U2 - 10.3390/nano14080713
DO - 10.3390/nano14080713
M3 - Article
C2 - 38668207
AN - SCOPUS:85191716176
SN - 2079-4991
VL - 14
JO - Nanomaterials
JF - Nanomaterials
IS - 8
M1 - 713
ER -