Optical fiber sensor for measuring a magnetic field or electric current

摘要

An optical fiber sensor which is adapted for use in combination with a horse shoe-type iron core comprises a substrate having a groove pattern established by a pair of elongated grooves kept away from and in parallel to each other, and a third groove intersected at right angles with the paired grooves, respectively, an optical fiber having a U-shaped portion which is inserted into and fixed in the groove pattern, and an optical modulation unit which is fixedly provided in a light path of the optical fiber placed in the third groove. The substrate is composed of a composite substrate which comprises a non-magnetic portion and soft magnetic portions fixed to the non-magnetic portion at opposite sides thereof. The paired elongated grooves are, respectively, formed in the soft magnetic portions, and the optical modulation unit is fixed to the non-magnetic portion. A method for making such a composite substrate is also described. <IMAGE>