LAUSR

The paper presents the fabrication of S-shaped metallic long period fibre grating (MLPFG) based on electroforming process for the realization of metal-based micro-electro-mechanical systems magnetic field sensors. The fabricated S-shaped MLPFG sensors were then tested in a magnetic field experiment. The NdFeB magnet was used to control the size of the magnetic field, and a gaussmeter was used to measure the magnetic field to analyse the spectral changes in the sensor in different magnetic fields. The results showed that an external magnetic load (NdFeB magnet) attracted the nickel structure, which changed the periodic metal structure size, disturbing the refractive index of the LPFG structure and altering the coupling coefficient, which increased the transmission loss as the magnetic field varied from 0 to 350 Gauss. The optimal sensitivity of the magnetic field to the loss was − 0.0084 dB/Gauss and R2 was 0.9426. Therefore, the S-shaped metallic LPFG sensor developed in this study can be used to detect magnetic fields.