Research progress in BIC active nanophotonic devices

Miniaturization and multifunctional integration have emerged as key trends in the development of nanophotonic devices. Nevertheless, achieving both strong light-matter interactions and versatile optical field control in a single device remains a significant challenge. Bound states in the continuum (BICs) provide a novel approach to addressing this issue. Acting as ultra-low-loss, open microcavities, BICs can effectively enhance light-matter interactions; while as nonlocal resonant metasurfaces, they enable flexible control of optical fields through precise symmetry and geometric design. This review summarizes recent progress on BIC-based metasurfaces in active nanophotonic devices, with a particular focus on their applications in linear and nonlinear optics, as well as in classical and quantum photonics. Future research directions are also discussed.