Magneto-optical fibre sensors for electrical industry: analysis of performances

We present an analysis of all-fibre sensors intended for current and magnetic field measurements in electrical systems. After reviewing magneto-optic effects in connection to application requirements, we calculate the theoretical performances of the sensor, in terms of sensitivity, bandwidth, dynamic range and linearity, both for polarimetric and interferometric readout schemes. Sources of errors in the fibre and optical components are analysed, and their limitations to sensitivity are evaluated. Birefringence control is discussed, and the results applied to develop several linked and unlinked sensor configurations. Finally, experimental data are compared to theoretical values.