All-dielectric metasurface realizing high-Q EIT via bound states in the continuum

We theoretically demonstrate a high-Q electromagnetically induced transparency (EIT) in an all-dielectric metasurface composed of a ring resonator coupled with a split-ring resonator (SRR) via bound states in the continuum (BIC). The transition from BIC to quasi-BIC state is achieved by tuning the asymmetry parameter. The quasi-BIC mode of the SRR strongly couples with the bright mode of the ring resonator, generating a sharp EIT peak with a high Q-factor of 4.26 × 10 5 . Furthermore, the EIT response exhibits strong polarization dependence, enabling dynamic switching by adjusting the incidence polarization angle. This work provides a promising platform for high-performance optical devices, including narrowband filters, sensors, and slow-light components.