| 摘要 |
PURPOSE:To superimpose with ease a subsignal on a main signal by changing the angle of Faraday rotation by controlling a DC magnetic field by use of a second Faraday rotator wound with a coil. CONSTITUTION:By controlling a DC current I flowing through a coil 9, a DC magnetic field H excited on the coil 9, i.e., a Faraday rotation angle theta is varied. Herein, since the plane of polarization of the light is rotated but the plane of polarization of a second analyzer 11 has been fixed, the light intensity incident upon an optical fiber 7 can be changed as a vector. Further, once the current, which is made to flow through the coil, is changed with the subsignal, the subsignal can be superimposed on a main signal. |
