| 摘要 |
<p>PURPOSE:To obtain a Faraday effect type optical fiber sensory from which a magnetic field sensor or a current sensor of high precision is obtainable by suppressing an adverse effect due to birefringence and a change in the birefringence (rotary polarization) due to temperature, and a current transformer using the same. CONSTITUTION:A right-rotation twist section and a left-rotation twist section are provided in an optical fiber of a single mode having a prescribed length, and the number of twists for a distance is made equal practically for these sections, while the accumulated number of twists in the right-rotation twist section and the accumulated number of twists in the left-rotation twist section are made equal practically to each other. The optical fiber thus prepared is held in a tube 9 and the tube 9 is wound round on a bobbin 8. Accordingly, the polarization plane maintaining property of the optical fiber is enhanced and the rotatory power due to temperature is canceled. Besides, highly accurate measurement of a current is enabled by a simple structure.</p> |
