Polarimetric current sensor using an in-line Faraday rotator

A novel polarimetric fiber optics current sensor configuration using an in- line 22.5 degree Faraday rotator is proposed on this paper. The introductio n of the 22.5 degree Faraday rotator allows to obtain a sensor configuratio n that does not require adjustment on most optical elements, resulting in a n accuracy immune to manufacturing issues. Two prototypes are presented in this paper that are designed to measure AC current, yielding in an excellen t accuracy over more than 3 decades.