| 摘要 |
<p>PURPOSE: To highly accurately measure current or magnetic field by removing an error due to imbalance in characteristics of a photoelectric transducing element or the like and fluctuation in a reference polarization azimuth of an optical fiber. CONSTITUTION: An optical fiber 4 is provided around a conductor 1 with electricity supplied. Laser light from a semiconductor laser light source 2 for supplying measurement light to the optical fiber 4 is converted into linearly polarized light by a polarizer 3 to be injected. A polarization surface of this light varies in a polarization angle by current I. Emitted light from the optical fiber 4 is separated into p-waves and s-waves by a light detector 5, transduced into a voltage signal by photo diodes 8a, 8b, and separated into AC components and DC components by separating means 11a, 11b. Then, a first component ratio and a second component ratio of the AC and DC components are respectively obtained by subtracting means 12a, 12b, and their product is obtained by a multiplying means 13. A value of the current I is measured from an output from the multiplying means 13.</p> |
