| 摘要 |
An optical variable attenuator is provided with: a plurality of polarizer means for extracting a predetermined polarized wave component from an input optical signal; polarized-wave rotating means composed of an array of Faraday rotators formed of a ferromagnetic material and arranged in series between the plurality of polarizer means, and magnetic field supply means provided for each Faraday rotator, for supplying thereto a magnetic field for rotating the polarized wave component of the optical signal; and polarization-rotating angle control means for setting polarization-rotating angles of the Faraday rotator array based on a combination of polarization-rotating angles each set for one of Faraday rotators by controlling the intensity of the magnetic field supplied thereto from by the magnetic field supply means. <IMAGE> |
