Tunable plasmon-induced transparency in double graphene split-ring resonator metasurface for high-sensitivity terahertz sensing
摘要
In this work, we present a tunable plasma-induced transparency (PIT) metamaterial architecture, ingeniously engineered from a graphene-based split-ring resonator metasurface. The core design integrates a leftward compact split-ring resonator (LSR) with its complementary rightward expanded counterpart (RSR), both meticulously tailored to stimulate planar bright modes. Simulations conducted using CST Studio Suite 2023 corroborate our theoretical framework, as Coupled Mode Theory (CMT) adeptly models the observed PIT spectral features. A thorough investigation into the geometrical dependencies revealed that parameters such as the inner and outer radii of the open rings, alongside the inter-resonator coupling distance, significantly influence the transmission spectrum. Notably, the tunability of the PIT window is achieved through modulation of the graphene’s Fermi level, underscoring the structure’s adaptive capabilities. The metamaterial exhibits a measurable slow-light effect, with a peak group delay of 0.642 ps. While this delay is moderate compared with multilayer or multi-resonator designs, it nonetheless demonstrates that the proposed structure can achieve useful dispersion control within a compact and simplified configuration. From a sensing perspective, our devices demonstrate excellent performance, characterized by a high refractive index sensitivity