A robust on-chip refractive index sensor assisted by magnetic plasmon polaritons

We have designed a metal-dielectric-metal (MDM) nanoantenna array that can support both localized surface plasmon (LSP) modes and magnetic plasmon polariton (MPP) modes. Due to the differences in environmental response among the modes, the array achieves a wide refractive index detection within range of 1.00–1.60. Its sensitivity reaches 522.76 nm/RIU. In addition, we also proposed a universal computing model for sensing under certain disturbances, indicating that the excessive emphasis on the stability of reference signal is unnecessary in self-reference sensing. Benefiting from the quasi-invariant property of magnetic plasmon resonance, the chip has been verified to maintain a significant detection accuracy even under certain perturbations. This work has potential applications in environmental sensing with integrated optics, as well as in the fields of biomedical research and diagnosis.