A Highly Sensitive Liquid–Filled Microstructured Fiber SPR Sensor for Refractive Index and Temperature Measurement

In this paper, we propose a linear three hole microstructured optical fiber surface plasmon resonance sensor to realize the detection of temperature and refractive index (RI). The sensing analytes are placed inside the central hole to guide light, and gold layers are coated on the inner surface of the side holes to generate surface plasmons. The sensor characteristics have been analyzed via finite element method-based software COMSOL Multiphysics. According to the numerical results, the proposed sensor exhibits average wavelength sensitivity of 33,160 nm/RIU (RI unit) with linear behavior in the RI range of 1.45–1.47. The minimum measurable variation by the sensor lies in the order of 10 −6 RIU, and maximum figure of merit is calculated to be 414.5. Besides, when applied for temperature detection, the sensor shows average temperature sensitivity of 9.08 nm/°C with excellent linearity. So, due to its simple structure and competitive sensing performance, the proposed sensor can be useful for sensing high RI analytes in the petroleum and chemical industry and for magnetic field and temperature measurement.