High-Q-factor electromagnetically induced transparency utilizing quasi-bound states in the continuum in an...

In recent years, electromagnetically induced transparency (EIT) has attracted extensive attention in the field of photonics. However, such effects typically arise from intricate bright-dark mode design and yield limited quality factors. In this study, an all-dielectric metasurface is experimentally validated to achieve EIT through coupled interactions between symmetry-protected bound states in the continuum (SP-BICs) and intrinsic resonant modes of the metasurface structure. Inheriting the high-Q-factor nature of BICs, the resulting EIT achieves a simulated Q-factor of 3802.61 and demonstrates a significantly strong slow-light effect in the terahertz band, exhibiting a group delay time of 1992.5 ps. This work establishes a new, to our knowledge, approach for EIT implementation via metasurfaces, with promising applications in narrowband filtering and slow-light devices. Moreover, this configuration exhibits superior performance metrics compared to comparable devices in the same category.