| 摘要 |
<p>PURPOSE:To obtain an optical magnetic field sensor which is suitable for measuring small magnetic fields by inserting a lens between a magneto-optical element and polarizer on the light receiving side. CONSTITUTION:While magnetic garnet is used as the material of a magneto- optical element 4, the light which becomes linearly polarized light after passing through a polarizer 3 and is made incident to the element 4 is diffracted and spreads as zero, first, second,..., n-th order light immediately after passing through the magnetic garnet of the element 4, because the garnet has a transmitting path-like magnetic domain. In order to prevent the diffraction, a lens 8 is inserted between the element 4 and a polarizer 5 so that diffracted rays of light from the zero order to higher order can be made incident to an optical fiber 7. Therefore, an optical magnetic field sensor which is suitable for measuring small magnetic fields can be obtained, because the magnitude of a magnetic field and the linearity of the sensor can be improved and the influence of temperatures on the output of the sensor can be eliminated and, at the same time, the phase angle can be reduced.</p> |
