Rugged fiber-optical current sensor based on the Faraday effect

摘要

A fiber-optical current transformer including a sensor coil, operated in reflection mode, with a sensor fiber (5) for detecting a current utilizing of the Faraday effect. A light source (1) couples light into an incoming first HB fiber (2a). At the end of the first HB fiber (2a), a fiber-optical polarizer (4) is preferably located which ensures a direction of polarization in parallel with a given birefringence axis of the first HB fiber (2a). A Y splitter (3) couples, on the one hand, the supplied light of the first HB fiber (2a) into the sensor fiber (5) and, on the other hand, the light coming from the sensor fiber (5) into an outgoing second HB fiber (2b). The second HB fiber (2b) is rotated with its birefringence axes by 45° with respect to the birefringence axes of the first HB fiber (2a).