Magnetic field sensor with truncated honeycomb photonic crystal fiber: analysis under the variations in magnetic fluid composition and temperature for high performance in near infrared

Abstract

A photonic crystal fiber (PCF)-based magnetic field sensor is simulated and analyzed by using a honeycomb fiber without the first ring of air holes where the core air hole is filled with a magnetic fluid which is surrounded by a gold layer. The variation of the refractive index with the magnetic field at a fixed wavelength (1557 nm) is considered for the study. The sensor is based on variation of the transmission loss of optical power with the magnetic field. The real part of the effective index increases with the magnetic field. The simulation and analysis is carried out at (i) three different temperatures (t = 24.3 °C, 40 °C, and 60 °C) and, (ii) for different values of the volume fractions (c = 1.21%, 1.48%, 1.52%, and 1.93%) of Fe3O4 particles in a magnetic fluid solution. All the concerned values of magnetic fluid refractive index are adapted from the previously-reported experimental work. The detailed analysis of the simulation results indicates that the proposed PCF sensor has the capability of providing high sensitivity, ultrafine resolution, and low thermal sensitivity. The variation of Fe3O4 provides another crucial degree of freedom to further enhance the sensitivity of the magnetic field detection. The sensor can provide a sensitivity of 4.3763 dB/Oe and magnetic field resolution of 2.2850 × 10–3 Oe for a large enough range (∆H = 163.87 Oe) of magnetic field (28.58 Oe ≤ H ≤ 192.45 Oe).