Design of a Photonic Crystal Fiber Sensor Based on Symmetric Lattices Filled with Magnetic Fluid

A photonic crystal fiber (PCF) sensor based on symmetric lattices filled with magnetic fluid (MF) was designed for sensing applications using surface plasmon resonance (SPR) technology. Using COMSOL multiphysics, we employed the finite element method (FEM) to investigate and optimize a range of structural parameters for the sensor. Subsequently, various structural parameters, such as gold film thickness and pore structure, were analyzed to assess their effects on performance. The resulting impacts on sensitivity, the full width at half-maximum (FWHM) of the loss peak, and the figure of merit (FOM) were evaluated. Following structural optimization, the proposed PCF sensor achieved a maximum wavelength sensitivity of 21807 nm/RIU in the MF refractive index (RI) range of 1.43316 to 1.43964. When the applied magnetic field strength varied from 50 to 250 Oe, the maximum magnetic field sensitivity was 1750 pm/Oe. The maximum resolution achieved was 0.1 Oe. This improved PCF sensor structure shows potential as a strong competitor in magnetic field detection applications.