A Selective Filling Photonic Crystal Fiber Voltage and Magnetic Field Dual-Parameter Sensor Based on Surface Plasmon Resonance

We proposed a photonic crystal fiber (PCF) sensor with selective filling of liquid crystal (LC) and magnetic fluid (MF) based on the principle of surface plasmon resonance (SPR) with the dual-parameter detection of voltage and magnetic field. Sodium is selected as the metallic material for coating into the four air holes in the second cladding of the PCF to excite the SPR phenomenon. Considering the relatively active chemical property of sodium, which is prone to react with water-based or kerosene-based MFs, an additional adhesive layer of titanium dioxide (TiO2) is deposited in the holes of the second cladding to protect the metal film. LC and MF are filled, respectively, in the four air holes of the second cladding of the PCF as sensitive materials to realize dual-parameter detection of voltage and magnetic field. By using the full vector finite element method (FEM) under the condition of the perfectly matched layer (PML), the sensing performance is analyzed in this work. The simulation results indicate that the sensitivity of the designed sensor in the detection range of voltage from 0 to 60 V and magnetic field intensity from 267 to 910 Oe can reach 5.107 nm/V and 1416 pm/Oe respectively, which has a high-quality linearity and preferable detection independence.