Generating different polarized multiple Fano resonances for highly sensitive sensing using hybrid graphene–dielectric metasurfaces

We demonstrate the perfect generation of four Fano resonances with different polarizations in the mid-infrared regime through a hybrid graphene-dielectric metasurface consisting of three pieces of silicon embedded with graphene sheets over the CaF2 substrate. Through monitoring the variations of polarization extinction ratio of the transmitting fields, a tiny difference of analyte refractive index can readily be detected from the drastic changes at Fano resonant frequencies in both co- and cross-linearly polarized components. Especially, the reconfigurable characteristic of graphene would be capable of tuning the detecting spectrum by pairwise regulating the four resonances. The proposed design should pave the way for more advanced bio-chemical sensing and environmental monitoring using metadevices with different polarized Fano resonances.