Simultaneous measurement of temperature and magnetic field based on directional resonance coupling in photonic crystal fibers

A dual-parameter sensor based on magnetic fluids (MF) infiltrated Photonic Crystal Fibers (PCFs) is proposed and its sensing performances have been studied numerically by the finite-element method (FEM). Based on the dependence of the MF refractive index on temperature and magnetic field, directional resonance coupling is introduced to achieve simultaneous measurement of temperature and magnetic field. Two defective channels are designed in the cladding layers to solve the cross-sensitivity problem. The mode coupling and the confinement loss spectra of core modes are investigated, and the spectral response of the device to magnetic field and temperature is characterized.