Non-Equidistant Arrangement in All-Dielectric Quadrumers and Mirror-Symmetric One-Dimensional Photonic Crystals Hybridstructure for Self-Referenced Sensing Scheme

All-dielectric nanostructures have attracted attention for highly efficient light manipulation. Higher Q-factor Fano resonance can be excited due to the rich phenomenology of optical modes supported by high-index dielectricmaterialswith lowintrinsic material loss, including both electric and magnetic multipolar Mie resonances. So far, there have been few studies done on the sensingwithFano-resonant all-dielectric resonator nanostructures. Here, an all-dielectric self-referenced optical sensor is numerically demonstrated based on Si quadrumers and mirror-symmetric 1-D photonic crystals (1DPCs) hybridstructure, operating at the infrared wavelength range with higher sensing performance and much more stable reference signal. Magnetic Fano resonance and Fabry-Perot resonance were combined into such a hybridstructure for the first time. The influences of the gap distance, including Delta x and Delta y, on the coupling effects between the Si nanodimers along the polarization direction and the 1DPCs are systematically discussed. The sensing performance has been numerically investigated in different analytes with the sensitivity and figure of merit (FOM) of 760 nm/RIU and 1515 RIU-1 respectively, which paves the way to be amuchmore sensitive detection of small refractive index changes in an unstable environment and suggests potential applications in biological and chemical sensing.