| 摘要 |
PURPOSE:To obtain the permanent magnet, the distribution of a magnetic field in an opening thereof does not display double-humped characteristics and which has flat and uniform characteristics, by magnetizing a columnar body with a section close to a circle in the direction crossing the side surface of the columnar body and forming the opening in parallel with the direction of magnetization. CONSTITUTION:A permanent magnet has circular opposite first and second planes 11, 12 and the side surfaces 13, and takes a columnar shape. The permanent magnet has the direction of magnetization in the direction crossing the side surfaces 13, and the opening 14 extending along the direction of magnetization is formed so as to penetrate the side surfaces 13. Magnetic field strength on an (x) axis displays extremely flat distribution, and the reduction of an extinction ratio due to inequality of the distribution of the magnetic field of the permanent magnet can be prevented when the magnet is applied to an optical isolator. |
