Triple frequency bands terahertz metasurface sensor based on EIT and BIC effects

How to improve the sensitivity of terahertz wave metasurface biosensors has always been a research hotspot in the field of biosensors. In this article, we propose a well-shaped all dielectric metasurface, which can simultaneously excite electromagnetic induced transparency (EIT) and bound states in the continuum (BIC) effects, achieving high sensitivity sensing at three frequency points. The maximum Q value of refractive index sensing is 69238, with a sensitivity of 535 GHz/RIU and the figure of merits (FoM) of 85468. Moreover, the structure exhibits EIT group delay effect, with a maximum group delay of 5.57ps. The results indicate that the well-shaped all dielectric metasurface enhances the interaction between terahertz waves and matter, which can not only achieve multi frequency terahertz high sensitivity sensing, but also be used for the design of new slow light devices.