Tunable quintuple plasmon-induced transparency and the effect of symmetry breaking based on monolayer graphene split rings metasurface

Abstract

A monolayer graphene metasurface composed of two large graphene split rings (TLGSRs) and two small graphene split rings (TSGSRs) is designed and proposed to achieve a tunable quintuple plasmon-induced transparency (QPIT) by coupled mode theory (CMT) and finite-difference time-domain (FDTD) simulations. We successfully realized and designed quintuple-frequency asynchronous, sextuple-frequency asynchronous, and sextuple-frequency synchronous photoelectric switches by dynamically adjusting the Fermi energy levels of graphene. The switches exhibit remarkable performance characteristics, including amplitude modulation degree (AMD) ranging from 71.0 % to 90.0 % and extinction ratio from 5.37 dB to 9.8 dB. The sensitivity of the proposed metasurface was studied and could reach 474 GHz/RIU. The proposed metasurface exhibits polarization-sensitive features due to its non-central symmetry in the metasurface. Finally, the metasurface symmetry-breaking effect on QPIT is further investigated, and results indicate that triple-PIT, quadruple-PIT, quintuple-PIT, and sextuple-PIT can be mutually transformed and regulated through structural symmetry breaking. In summary, the findings provide valuable guidance for the design of optoelectronic switches, sensors, and modulators.