We demonstrate experimentally refractive index sensing with localized Fano resonances in silicon oligomers, consisting of six disks surrounding a central one of slightly different diameter. Owing to the low absorption and narrow Fano-resonant spectral features appearing as a result of the interference of the modes of the outer and the central disks, we demonstrate refractive index sensitivity of more than 150 nm RIU
−1
with a figure of merit of 3.8.
This article is part of the themed issue ‘New horizons for nanophotonics’.
High-Sensitivity Refractive Index Sensing Based on Fano resonances in a Photonic Crystal Cavity-Coupled Microring Resonator