| 摘要 |
<p>PROBLEM TO BE SOLVED: To obtain an optical-fiber current measuring apparatus by which, when a magnetic field due to a high-voltage current flowing in a conductor is measured by making use of the Faraday effect of an optical fiber so as to measure the amplitude and the phase of the current, a low-cost general-purpose product can be used and which simplifies the connecting operation of a magnetic-field detection part arranged so as to be adjacent to a high-voltage apparatus to a transmission part. SOLUTION: A low-cost single-mode optical fiber 55 whose diameter is nearly identical to that of a single-mode optical fiber 61 for detection is used for transmission of light. Thereby, an optical axis can be aligned easily. In addition, a laser diode 65 at an oscillation wavelengthλwhich is smaller than the cutoff wavelength c of the single-mode optical fiber 55 is used as a light source. Thereby, incident light from the laser diode 65 is transmitted through the single-mode optical fiber 55 in a multimode, and it is transmitted to a magnetic-field detection part 53 without being affected by a vibration and a stress. Consequently, the complicated operation of the alignment of a plane of polarization can be eliminated.</p> |
