▎ 摘　　要

We propose an ultranarrow high-order Fano resonance generated by the plasmonic coupling between a hybridized quadrupole mode formed by plasmon hybridization of graphene nanoribbon dimer and a broad magnetic dipole mode from metallic split rings in a hybrid metamaterial. The results reveal that the high-order Fano curve is very narrow and indicates a large quality (Q) factor of 110. The ultrahigh-Q high-order Fano resonance can be convenient tailored by tuning Fermi levels and structural parameters. Our designed ultrahigh-Q hybrid metamaterial exhibits a high optical sensitivity of 4 mu m/RIU and figure of merit (FOM) of 44, which is very helpful to design high-sensitive sensors. (C) 2020 The Japan Society of Applied Physics.