Ultrahigh-Sensitive D-Shaped Double-Hole Fiber-Based Dual-Parameter Sensor for Simultaneous Detection of Magnetic Field and Temperature

A dual-parameter sensor based on a D-shaped double-hole fiber (DDHF) is designed for magnetic field and temperature detection. The DDHF is constructed by side-polishing a double-hole fiber to form an arc-shaped groove. By filling the magnetic fluid (MF) and polydimethylsiloxane (PDMS) into the exclusive air hole and the arc-shaped groove, respectively, simultaneous detection of magnetic field and temperature can be achieved. To further improve the sensitivities, two metal wires are arranged at the positions closest to the fiber core in the air hole and the arc-shaped groove to excite surface plasmon resonance (SPR). Numerical simulations demonstrate that the sensor can simultaneously detect magnetic field in the range between 35 Oe and 155 Oe and temperature between 24.3 °C and 84.3 °C. The maximum magnetic field sensitivity and maximum temperature sensitivity are 104,000 pm/mT and 9.5 nm/°C, both of which outperform previously reported sensors by more than one order of magnitude. In addition, the fabrication feasibility and tolerance of the sensor are evaluated. Featuring high sensitivity, easy materials modification, and no requirement for specialized packaging, the DDHF-based dual-parameter sensor has immense potential in applications such as biological analysis and environmental magnetic field monitoring.