| 摘要 |
<p>PURPOSE:To improve accuracy and reliability in measuring a conductor to be measured which is at high temperature by setting a slit having a circular hole whose diameter is smaller than that of a light beam in the light beam outgoing part/incoming part of an optical head. CONSTITUTION:The slit 25 having the circular hole whose diameter is smaller than that of the light beam is provided on the preceding stage of the lens 10 on a light emitting side of the optical head 5 consisting of a polarizer 8, a photodetector 9, the lens 10 on the light emitting side, a lens 11 on a light receiving side and the end surfaces of optical fibers 12 and 13. The light beam from the end surface 12 passes through the lens 10 and the slit 25 and is made incident on the Faraday effect material 1. The light beam transmitted through the effect material 1 is received by the end surface 13 through the photodetector 9 and the lens 11. In such a constitution, the optical axes of three-phase linear polarized light are made to coincide with each other by means of the slit 25 and also the relative value of received light quantity becomes equal. Therefore, high accuracy and high reliability can be obtained in the case that the conductor to be measured is at high temperature.</p> |
