High-Q Fano resonance in all-dielectric metasurfaces for molecular fingerprint detection

Abstract

We present and numerically investigate a high-quality factor (high- Q ) meta-atom with Fano resonance. Numerical simulations indicate that the designed meta-atom has a single sharp Fano resonance in the 1350–1750 1/cm range. Moreover, the frequency of the single resonance can be tuned in this frequency range by scaling the meta-atom. We exploit these properties to design a pixelated metasurface for spectrometer-less molecular fingerprint retrieval. The proposed meta-atom with an average quality factor of 2000 makes it possible to decrease the scaling step of metapixels without introducing resonance overlap between the metapixels, leading to higher precision in label-free and nondestructive identification of molecular fingerprints.