RECENT ADVANCES IN OPTICAL CURRENT-SENSING TECHNIQUES

The Faraday effect is becoming widely used as an optical method of mea suring electric current or magnetic field. It is particularly advantag eous where the measurements must be made at high voltage or in the pre sence of electromagnetic interference, and where speed or stability ar e considerations. In this paper, the present state of research into Fa raday-effect current sensors is outlined, eight possible approaches fo r overcoming the problems associated with the linear birefringence ins ide the fibres of optical current sensors are simply introduced, recen t advances in this area are reviewed, and possible prospects are consi dered.