All-dielectric metasurfaces with high Q-factor Fano resonances enabling multi-scenario sensing

Abstract We propose and numerically demonstrate high Q-factor sensors based on all-dielectric metasurfaces, which are very sensitive to the change of refractive index surrounding media incident angle. By using light angular scanning method, metasurface symmetric tetramer can act as an excellent sensing platform for trace-amount molecules such protein A/G, 2, 4-DNT, 2D material graphene with huge absorbance enhancement in mid-infrared broadband spectrums. The results reveal that envelope amplitudes is good agreement vibrational mode molecules, factors reach 10 dB wavelength range from 5.75 6.80 μm. To further increase resonances, asymmetric investigated. This structure induce toroidal magnetic dipoles governed by quasi-BIC produce multi-extremely narrow linewidth Fano maximum sensitivity reaches up 1.43 μm/RIU. Therefore, proposed demonstrates highly enhanced performance chemical information biomolecules, inspires development new high-sensitivity nondestructive identification regime.