Experimental demonstration of a metal–dielectric metamaterial refractive index sensor

•A metamaterial equipment is designed and experimental verified.•The metamaterial equipment is independent of polarization.•The metamaterial equipment is sensitive in the refractive index.•The metamaterial equipment can be applied in sensing field. A metamaterial equipment is designed and experimental verified in the near-infrared with two reflectivity dips. The metamaterial equipment shows independent of polarization. Simulated results indicate that the reflectivity dip is excited by the coupling of localized surface plasmon (LSP) modes. The metamaterial equipment can work as a refractive index detection sensor with high figure of merit (FOM) value. This proposed metamaterial sensor can be applied in detecting different biochemical liquid.