| 摘要 |
PURPOSE:To attain the miniaturization and light weight of an optical isolator by modifying the shape and arrangement of a permanent magnet for use of Faraday element magnetization and to improve the recording and reproducing characteristics of an optical disk driving device by providing such optical isolator. CONSTITUTION:Two permanent magnets 12, 13 are arranged on the optical paths on both sides of a Faraday rotator 11 facing in a direction where an attracting force interacts with each other. It is especially desirable that the permanent magnets are formed in truncated conical shape, and they are arranged facing their minor diameter terminals on a Faraday rotator side. The optical isolator 1 is provided to the projection optical system 32 of the optical disk driving device, and it also shares polarizing beam splitters(PBS) which introduce return light from an optical disk 21 to a signal detection optical system 33 or an optical system 34 for monitoring use as two PBSs 39, 40 which comprise the optical isolator. |
