Beyond Conventional Sensing: Hybrid Plasmonic Metasurfaces and Bound States in the Continuum

Abstract

Fano resonances result from the strong coupling and interference between a broad background state and a narrow, almost discrete state, leading to the emergence of asymmetric scattering spectral profiles. Under certain conditions, Fano resonances can experience a collapse of their width due to the destructive interference of strongly coupled modes, resulting in the formation of bound states in the continuum (BIC). In such cases, the modes are simultaneously localized in the nanostructure and coexist with radiating waves, leading to an increase in the quality factor, which is virtually unlimited. In this work, we report on the design of a layered hybrid plasmonic-dielectric metasurface that facilitates strong mode coupling and the formation of BIC, resulting in resonances with a high quality factor. We demonstrate the possibility of controlling Fano resonances and tuning Rabi splitting using the nanoantenna dimensions. We also experimentally demonstrate the generalized Kerker effect in a binary arrangement of silicon nanodisks, which allows for the tuning of the collective modes and creates new photonic functionalities and improved sensing capabilities. Our findings have promising implications for developing plasmonic sensors that leverage strong light-matter interactions in hybrid metasurfaces.

Optical bound states in the continuum in periodic structures: mechanisms, effects, and applications

“…By carefully designing the perovskite-based metasurfaces, it is possible to increase the Rabi splitting to over 200 meV [163,164] . Moreover, without special emitters like TMDCs or perovskites, the strong coupling can still be reached by carefully designing BIC photonic plasmonic/ dielectric structures [32,[165][166][167][168][169][170][171] .…”

Optical Processes behind Plasmonic Applications

“…In plasmonic sensors, various phenomena, such as BIC, Fano resonance, and the Kerker effect, can be utilized to enhance detection and sensing capabilities [ 139 ]. Bound state in the continuum allows for the confinement of light in a subwavelength structure with almost perfect reflection, whereas Fano resonance enables high sensitivity and selectivity in sensing applications by utilizing the interference between a broad and a narrow resonance [ 140 ]. On the other hand, the Kerker effect involves controlling the scattering direction of an incident light by designing a resonant structure with specific geometries and materials.…”

Multipole Mie Resonances in MXene-Antenna Arrays

“…The electric and magnetic dipole and quadrupole moments of an antenna refer to the characteristics that describe the distribution and strength of its electric and magnetic fields, which play a significant role in determining the antenna’s radiation pattern and performance. Mie resonances are electromagnetic resonant responses that can occur in low-loss high-refractive-index or metallic nanoparticles and arise due to the interaction of light with the nanoparticle. − By incorporating metals and/or high-refractive-index materials into nanostructures, it is possible to achieve nanoscale light confinement and adaptable designs for controlling the optical field. ,− Plasmonic nanostructures take advantage of Mie resonances to efficiently manipulate light at the subwavelength scale.…”