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

A high-sensitivity triple-parameter sensor based on surface plasmon resonance (SPR) in a D-type photonic crystal fiber (PCF) is proposed. The sensor incorporates a Y-shaped sensing channel that enables the simultaneous and independent detection of three parameters with high sensitivity and minimal cross-interference. By integrating silver and gold in the form of thin film and nanowire, the sensor can simultaneously measure the external magnetic field, ambient temperature, and analyte refractive index with high accuracy. The finite element method (FEM) is used to analyze the effects of structural parameters on the sensing performance, and the design is optimized accordingly. Numerical results show that the sensor achieves a magnetic field sensing sensitivity of 2.06 nm/mT within the range of 0–80 mT, a temperature sensing sensitivity of 9.2 nm/°C within the range of -5 to 30°C, and a refractive index sensing sensitivity of 28,000 nm/RIU within the range of 1.405–1.425. Owing to its simple structure and high sensitivity, the sensor is not only easy to fabricate and integrate, but also well-suited for complex application scenarios that require high detection accuracy, such as biological, chemical, and marine sensing.