Three-Channel Photonic Crystal Fiber Sensor for Simultaneous Measurement of Magnetic Field, Temperature, and Refractive Index

This study presents a magnetic field-temperature-refractive index sensor based on surface plasmon resonance (SPR) and photonic crystal fiber (PCF). The sensor integrates three independent sensing channels, offering high sensitivity with minimal cross-interference. By utilizing silver and gold in the form of thin films and nanowires, the sensor can simultaneously and accurately measure the external magnetic field, ambient temperature, and refractive index of the analyte. The influence of structural parameters on the sensor performance was analyzed using the finite element method (FEM), with subsequent optimization of these parameters. The sensor’s temperature sensing range spans 0 °C–100 °C, with a wavelength sensitivity (WS) of 6.6 nm/°C. The magnetic field sensing range is 0–100 mT, with a WS of 0.75 nm/mT. The refractive index sensing range is 1.410–1.435, with a WS of 29 800 nm/RIU. With the features of high sensitivity, wide detection range, and excellent linear response, this sensor shows significant potential for applications in biology, chemistry, and marine exploration.