Optical fiber sensor for measuring a magnetic field or electric current and method for making the same

摘要

An optical fiber sensor which is adapted for use in combination with a horseshoe-type iron core comprises a substrate having a groove pattern established by a pair of elongated spaced, parallel grooves, and a third groove which intersects the paired grooves at right angles. An optical fiber having a U-shaped portion 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, is placed in the third groove. The substrate is a composite which comprises a non-magnetic portion and soft magnetic portions fixed to either side of the non-magnetic portion. The paired elongated grooves are formed in the soft magnetic portions, while the optical modulation unit is fixed to the non-magnetic portion. A method for making such a composite substrate is also described.