Surface plasmon polariton high-sensitivity refractive index sensor based on MMF-MOF-MMF structure

A surface plasmon resonance (SPR) refractive index (RI) sensor composed of a multimode fiber-microstructure fiber-multimode fiber (MMF-MOF-MMF) structure is studied. The experimental results show that the sensor has good linearity (R-square = 0.96912) in the refractive index detection range of 1.3328–1.3990, and the sensitivity is as high as 3223 nm/RIU. Moreover, the sensor shows excellent temperature insensitivity within the temperature fluctuation range of 25–46 °C. In addition to good linearity and high sensitivity, the proposed SPR sensor with MMF-MOF-MMF structure also has the advantages of compact structure, easy manufacturing and good reproducibility. Therefore, it can be used to detect chemical and biological analytes.