Abstract
A refractive index sensor can provide refractive index measurement and continuously monitor a dynamic process. Plasmonic nanostructure based sensors suffer from severe metal losses in the optical range, leading to the performance degradation. We design and numerically analyze a high-performance refractive index sensor based on the Fano resonance generated by a dielectric metasurface. The figure of merit (FOM) and the maximum quality factor (Q-factor) of the sensor are 721 and 5126, respectively. The maximum modulation depth can exceed 99% and the enhancement factor of the electric field amplitude can reach a high value of about 100. The uniqueness of the proposed sensor is polarization insensitivity. The transmittance spectra for various polarization states of the incident light can perfectly coincide, which is a rare phenomenon in Fano resonance based sensors and can facilitate experimental measurement.
Highlights
Metasurfaces are two-dimensional counterparts of metamaterials, which have aroused great interest due to their unprecedented capability in the manipulation of light propagation [1,2,3,4]
A refractive index sensor with a sensitivity that can exceed 500 nm/RIU was reported by etching H-shaped aperture structure on the gold film [19], but its figure of merit (FOM) is only 3.8
The proposed refractive index sensor consists of a TiO2 nanostructure sitting on a glass substrate
Summary
Metasurfaces are two-dimensional counterparts of metamaterials, which have aroused great interest due to their unprecedented capability in the manipulation of light propagation [1,2,3,4]. The generation of Fano resonance usually requires the structure to be asymmetric [32], meaning that the sensor made by this kind of metasurface is sensitive to the polarization of the incident light, which causes the inconvenience for measurement.
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
