PURPOSE: To achieve smaller size, lighter weight and higher performance by using a permanent magnet for magnetization of a ferromagnetic material for Faraday rotation and magnetically connecting the same with a yoke thereby forming the closed magnetic path of bottomed cylinder form.
CONSTITUTION: A ferromagnetic material 4 of column form for Faraday rotation are so provided as to contact the end parts of columnar form parts 16, 17. Hence, the magnetic flux is transmitted from a magnet 14 via the central columnar form part 17 of the yoke 13 to the ferromagnetic material 4 to saturation-magnetize said material and returns via the yoke 12 to the magnet 14 thereby forming a closed magnetic path. At this time, the thickness and value of magnetization of the magnetic material 4 are so selected as to give Faraday rotation of 45°. Since the Faraday rotor by this constitution forms a closed magnetic path, it is magnetically stable and the optical isolator of small size, light weight and high performance may be obtained
IWAMURA HIDETOSHI
SUEMUNE YASUTAKA
| JP38025901A |