Bilaterally Polished Photonic Crystal Fiber Magnetic Field Sensor Based on Lossy Mode Resonance

A kind of magnetic field sensor is proposed, which is based on symmetrically side-polished photonic crystal fiber (PCF) with regular hexagonal air holes. Magnetic fluid (MF) is used as the magnetic field-sensitive material. The polished surfaces are coated with an indium tin oxide (ITO) film to generate lossy mode resonance (LMR) for magnetic field sensing. The obtained magnetic field sensitivity is 466.81 pm/Oe, which can be further adjusted by changing the thickness of the ITO film. The comprehensive sensing performance is evaluated by defining the figure of merit (FOM). The proposed structure is simple and has the capability of mass production, which has great development space in the future.