Interferometric Fiber-Optic Magnetic Field Sensor

A fiber-optic interferometer sensitive to variations in the constant magnetic field is presented. A magnetostrictive material is used as its sensitive element. The sensor is based on the Fabry–Perot interferometer with the length determined using a unique signal processing algorithm, which allows the measurement accuracy to be improved by two orders of magnitude. Advantages of the sensor are a high dynamic range, small size, and standard components. The working range of the sensor is $$B \leqslant 50{\text{ mT}}$$ and the dynamic range is 84 dB. Recommendations are given for increasing the system sensitivity and the measurement accuracy.