In this paper we report on the use of low-loss fused-silica-plastic optical fibers as magneto-optic current-measuring devices. The fiber is wound around a conductor, and linearly polarized laser light is launched into the fiber core. A current flowing through the conductor will generate a longitudinal magnetic field within the fiber, which in turn will rotate the direction of polarization of the guided light. This so- called Faraday rotation is measured opto- electronically at the fiber end and serves as a measure for the amount of current flow. A precondition for accurate current measurements is that the degree of polarization of the guided light be maintained over the entire fiber length.
© 1979 Optical Society of AmericaPDF Article