| 摘要 |
PURPOSE: An optical fiber current sensor and a sensing method thereof are provided to allow a high precision and a high sensitivity of measurements by blocking influences due to changes of external circumstances such as temperature changes, vibrations, magnetic fields etc. CONSTITUTION: A photogeneration part modulates a generated light into a carrier frequency, and provides as an input light. A polarizing beam processing unit changes the input light into a first polarizing beam and a second polarizing beam, which rotate in opposite directions with each other. In the sensing optical fiber(150), the first polarizing beam and the second polarizing beam income from the polarizing beam processing unit are reciprocated, and a phase difference between the first polarizing beam and the second polarizing beam based on the Faraday effects by current is provided. An optical detector(170) is optically connected to the polarizing beam processing unit. If he first polarizing beam and the second polarizing beam which are reflected at the end of the sensing optical fiber are filtered to linear polarizing beams having flat polarizing surface by the polarizing beam processing unit, intereference optical signals of the filtered linear polarizing beams are received and are transformed into electric signals. A signal processing unit(180) calculates a size of the current flowing in a wire with reference to the electric signals. |
