High Q-factor resonances based on bound states in the continuum in an all-dielectric metasurface with sensing application

All-dielectric metasurfaces, when integrated with the theory of Bound states in the continuum, have recently attracted considerable interest. This combination offers a novel approach to enhancing light-matter interactions. This integration establishes a crucial platform for advancing the sensing capabilities of high-performance optical devices. Our study proposes an all-dielectric metasurface in the near-infrared band composed of silicon nanorod layers placed on top of a silica substrate. Two fano resonances are observed when the nanostructure maintains symmetry at the wavelengths of λ = 1007 nm and λ = 1071 nm and upon breaking the in-plane symmetry with an asymmetry parameter, δ, three sharp Fano resonances are excited, with a new asymmetric resonance profile emerging at λ = 1013 nm, resulting in a maximum Q-factor exceeding 106. Simulation results show that the developed metasurface may be tuned to satisfy the needs of various applications in the near-infrared range by modifying the structural characteristics. The designed structure presents an exciting opportunity for a wide range of applications, including nanosensors, optical switches, and nonlinear optics.