Research on an all-medium two-parameter metasurface sensor based on Fano resonance.

Compared to metallic metasurfaces, all-dielectric metasurfaces exhibit significantly lower losses and offer superior sensing performance. However, most existing metasurfaces are limited to single-parameter sensing and exhibit sensitivity to the incident angle of the light source. In this paper, we design and analyze an all-dielectric dual-parameter sensor that leverages structural asymmetry. The sensor consists of an array of silicon elements arranged on a quartz substrate. This metasurface excites two distinct Fano resonance peaks within the near-infrared spectrum, both corresponding to magnetic dipole modes. These resonance peaks demonstrate excellent polarization insensitivity and enhanced stability under oblique incidence. The study demonstrates that this design achieves outstanding performance in biosolution sensing, with a maximum refractive index sensitivity of 404.43 nm/RIU and a maximum temperature sensitivity of 51.76pm/°C.