| 摘要 |
PURPOSE:To prevent the luminance modulation from being applied to the connected part of an optical fiber and a waveguide type optical switch by providing a polarization plane modulator for applying vibration in the direction of an input terminal of the waveguide type optical switch of the optical fiber at a higher speed by several- cores of folds or above than a turn-on/turn-off signal of the waveguide type optical switch. CONSTITUTION:By a polarization plane modulator 3 which is provided between an emitting end-side of an optical fiber 1 and a waveguide type optical switch 2, and in which a part of the optical fiber 1 expands and contracts by, for instance, a voltage, a propagation light in the optical fiber 1 is subjected to polarization plane modulation forcibly at a higher speed by several - scores of folds or above than switching speed of the waveguide type optical switch 2. In such a way, a plane of polarization of the propagation light rotates several times-scores of times or above at a high speed within a switching time of the waveguide type optical switch 2. Therefore, the number of times by which the plane of polarization coincides with the X direction increases, and the propagation light is coupled easily to the waveguide type optical switch 2. Accordingly, the luminance modulation is scarcely applied and the modulator becomes a stable one. |
