ARF Dual-Channel Magnetic Field and Temperature Sensor Based on the SPR Effect

An anti-resonant fiber (ARF) surface plasmon resonance (SPR) dual-parameter sensor is designed for simultaneous detection of the magnetic field and temperature. Both sides of the fiber core in the sensor are filled with gold nanowires and gold dielectrics, respectively, to excite SPR. The center air hole in the ARF is filled with a magnetic fluid (MF) which responds to the magnetic field and temperature, and the temperature measurement is carried out by putting polydimethylsiloxane (PDMS) outside the gold nanowires. Analysis by the finite element method reveals maximum first and second resonance peak sensitivities of 300 pm/Oe and 500 pm/Oe, respectively, when the magnetic field is between 50 and 130 Oe. The maximum wavelength sensitivity of the second resonance peak is 10.8 nm/°C in the temperature range of 20–30 °C. Temperature cross-sensitization due to the magnetohydrothermo-optical effects is overcome by building and demodulating the sensing matrix. This new sensor design is very promising in fields such as industrial automation, military application, and geological exploration.