| 摘要 |
<p>PROBLEM TO BE SOLVED: To make it possible to measure a large current and to attain highly accurate measurement. SOLUTION: Laser beam from a light source is transmitted by a transmitting optical fiber 5, linearly polarized by a polarizer 4 and made incident upon and optical fiber 3. Core glass of the fiber 3 consists of high lead glass of which photo elastic constant at transmission wavelength is substantially zero and Verdet's constant is <5.8×10<-6> rad/A. Light made incident upon the fiber 3 undergoes, while passing through the fiber 3 rotation of the polarization plane in proportion to a current allowed to flow into a conductor 1 by a magnetic field formed by the current, and is projected. The outgoing light is passed through a 1/2 wavelength plate 6 and divided into two arthogonally polarized components, T, R by an analyser 7 and a prism 8, respective polarized components T, R are sent to a signal processing part through respective light receiving fibers 9, 10 and the current value of a current allowed to flow into the conductor 1 is calculated.</p> |
