FARADAY ROTATOR

摘要

OF THE DISCLOSURE The present invention provides a means of erasing the magnetic hysteresis with respect to a rare-earth iron garnet single-crystal film with large magnetic hysteresis which is an obstacle in using as a Faraday rotator although the film has extremely small saturated magnetic field intensity. In the present invention, a permanent magnet is positioned on a part of a rare-earth iron garnet single crystal. According to the present invention, the magnetic hysteresis can be erased with respect to a rare-earth iron garnet single-crystal film with large magnetic hysteresis which is an obstacle in using as a Faraday rotator although the film has extremely small saturated magnetic field intensity. As the result, an optical switch utilizing Faraday effect and a magnetooptical sensor with a Faraday rotator applied a rare-earth iron garnet single-crystal film which has small saturated magnetic field intensity are enabled to utilize practically.