摘要： The optical properties of high-performance concentric double metal-insulator-metal (MIM) rings is simulated and investigated with different refractive index ni of materials in the inner ring. By changing the refractive index ni , the wavelengths of resonant dips and coupling strength between the inner and outer rings can be highly tunable. The energy distribution ratio between the inner and outer rings can be also modulated. It is worth noting that when the energy distributes mainly in the inner ring, the energy loss to the bus waveguide can be suppressed efficiently and ultra-high quality (Q) factor can be got for this structure. When the energy in the outer ring is large, the coupling strength between the concentric double MIM rings and bus waveguide is strong and the extinction ratio for this structure can be very high. The concentric double MIM rings we proposed provides a new perspective to design the advanced plasmonic resonant cavity.