Engineering Fano‐Resonant Hybrid Metastructures with Ultra‐High Sensing Performances

Abstract

Metamaterials‐based sensors are of primary interest in physics, materials science, medicine, and biophysics thanks to their ability to detect very tiny amount of molecules spread into a medium. Here, a metastructure utilizing the epsilon near zero (εNZ) and Fano–Rabi physics is engineered to design a system with ultra‐high sensitivity. So far, a dedicated study of such systems has been missing. In this work, the authors report the results of their efforts to fill the gap by considering a metasurface, designed as a periodical array of rings with a cross in their center, placed on top of a silver (Ag) and zinc oxide (ZnO) epsilon near‐zero optical nanocavity (εNZ‐ONC) metamaterial. The accurate selection of the metasurface parameters allows the design of a sensor exhibiting an extremely high sensitivity of about 16 000 and 21 000 nm RIU−1 depending on incoming polarization. This work paves the way for the development of novel groundbreaking devices for biomedical and environmental application based on plasmonic and photonic design principles.

Unlocking Optical Coupling Tunability in Epsilon‐Near‐Zero Metamaterials Through Liquid Crystal Nanocavities

“…They were already reported in the supporting Information of the previous manuscript including a link to an open repository of such data. [ 14 ]…”

“…Nowadays, this approach is recognized as a cornerstone of fabrication technology, particularly in the development of high‐performance nano‐devices. The Fabry‐Perot resonator is one of the most convenient and broadly used devices in photonics, particularly for engineering light‐matter coupling [ 1–3 ] and is commonly used in color filters, [ 4,5 ] two‐photon direct laser writing with hyper‐resolution, [ 6,7 ] optical metasurfaces, [ 8,9 ] high‐heat release, [ 10,11 ] sensing devices, [ 12–14 ] and anti‐counterfeiting tags, [ 15 ] just to name a few. The resonant cavity is usually fabricated by sandwiching a transparent dielectric layer between two partially reflecting mirrors.…”

Multi-Wavelength Selective and Broadband Near-Infrared Plasmonic Switches in Anisotropic Plasmonic Metasurfaces

“…Recently, it is notable that plasmonic Fano resonance (FR) is a fundamentally interesting phenomenon derived from the interference between broad superradiant and narrow subradiant modes, thus leading to strong field enhancement and wavelength selectivity with sharp asymmetric spectral ling shape. This can enable the FR-based applications, such as optical sensing [22][23][24][25][26], switching [26][27][28][29], modulators [30][31][32], filter [33], and BICsupporting metadevices [20,34,35]. The multiple FRs, which can incur multi-wavelength selectivity at several spectral positions, are capable of outperforming the single plasmonic FR and can offer a variety of new attractive features in plasmonic metasurfaces due to being more sensitive to the structural parameters and the electromagnetic parameters of surrounding media [36].…”

Surface-Enhanced Raman Spectroscopy on an As-deposited Fano Resonance Multilayer Substrate

“…On the other hand, thin film multilayer systems can represent a very interesting alternative owing to their outstanding effects such as electromagnetic mode confinement, plasmonic effect, self-collimation, and sharp resonances that found application in several fields as sensing, − structural color, , anticounterfeiting, − and cooling , to name a few.…”