Temperature-Compensated Highly Sensitive Reflective SPR Fiber Sensor Based on Tapered Seven-Core Fiber

Temperature interference is often inevitable for fiber-optic sensors in various practical applications. In this article, a reflective surface plasmon resonance (SPR) sensor based on a tapered multimode fiber (MMF) and seven-core fiber (SCF) structure is proposed for simultaneous measurement of RI and temperature. Along the SCF, polydimethylsiloxane (PDMS) film is applied to the Au-coated surface near the Ag-reflector to achieve the simultaneous measurement function and protect the silver film. To get a better sensing performance, the waist diameter is optimized by simulation and experiment. In the experiment, the maximum sensitivities of RI and temperature of the proposed sensor reach 2078 nm/RIU and −2.76 nm/°C, respectively. Furthermore, the reflective dual-parameter SPR sensor allows fewer samples and simplifies the measurement process, which has great potential in environmental monitoring, disease diagnosis, and biochemical sensing.