Plasmon-induced transparency based on a molybdenum disulfide film terahertz metasurface for sensing applications

Abstract In this study, we proposed a bifunctional sensor of high sensitivity and slow light based on monolayer MoS 2 / TOPAS structure in the terahertz range. The proposed metamaterial is formed by a structured unit matrix that combines square and cross shapes made of MoS 2 and TOPAS . The plasmon-induced transparency (PIT) spectra appeared under the excitation of a transverse magnetic (TM)-polarization wave, the proposed PIT effect is originated from the near-field coupling of two bright modes. The Lorentzian mode theory spectrum describes the destructive interference between the two bright modes, and the fitted results are consistent with the Finite-Difference Time-Domain (FDTD) simulation results. Furthermore, the effect of geometrical sizes, like coupling distance, structure size, and intersection angle between square and cross shape on the PIT window is analyzed, along with the effects of carrier concentration in MoS 2 . A figure of merit of 1.10 RIU − 1 is obtained. The slow light performance of the proposed MoS 2 -based metamaterial is investigated, a maximum time delay of 0.52 ps is obtained and the delay band width product (DBP) is 0.76. It is more efficient to store and transmit the information over signal channels. Therefore, the proposed MoS 2 -based metamaterial can be used in electromagnetically induced transparency applications, such as sensors, optical memory devices, and flexible terahertz functional devices.