Controllable distant interactions at bound state in the continuum

Distant interactions at arbitrary locations and their dynamic control are fundamentally important for realizing large-scale photonic and quantum circuits. Conventional approaches suffer from short coupling distance, poor controllability, fixed locations and low wavelength uniformity, significantly restricting the scalability of photonic and quantum networks. Here, we exploit the intrinsic advantages of optical bound state in the continuum (BIC) and demonstrate an all-in-one solution for dynamically controllable long-range interactions. A BIC metasurface can support a series of finite-sized quasi-BIC microlasers at arbitrary locations. Such quasi-BICs microlasers have the same wavelength and are inherently connected through the BIC waveguide. As a result, the coupling distances are significantly increased from subwavelength to tens of micrometers in experiment. Ultrafast reconfigurability of lasing actions has also been realized by scaling individual photon sources to a two-dimensional architecture. This research shall facilitate the advancement of scalable and reconfigurable photonic systems for optical and quantum information processing.