Reflective Refractive Index Sensor Based on Surface Plasmon Resonance with MMF-SMF Structure

Abstract

A reflective and high-sensitive refractive index sensor was proposed based on surface plasmon resonance (SPR) with multimode fiber-single mode fiber (MMF-SMF) structure coated with gold film. In order to verify the performance of the reflective sensor, we also made a transmitted SPR sensor based on the multimode fiber-single mode fiber- multimode fiber (MMF-SMF-MMF) structure as comparison. The experiment results showed that the sensitivity of the reflective sensor reached 2029.3 nm/RIU in the refractive index range of 1.3338-1.3804, which was higher than the sensitivity of the transmitted sensor with sensitivity of 1888.8 nm/RIU. Moreover, the reflective probe is robust, easily packaged and suitable for remote measurement.