Polycrystalline Silicon metasurfaces enabling multi-scenario sensing applications in the mid-infrared

This paper presents the design and the fundamental operating principles of all-dielectric metasurfaces devoted to multiple gas/liquid sensing applications in the mid-infrared range. These metasurfaces are composed of silicon meta-atoms fabricated on either CaF
2
or $\mathrm{Si}_{3} \mathrm{~N}_{4}$ layers. We will compare the performances of both configurations and discuss advancements in optimizing such resonant structures to achieve near-field enhancement for improved sensing capabilities.