| 摘要 |
PURPOSE:To solve the problem of S/N deterioration owing to transmit analog data through direct modulation of light signal by providing a gap in the optical reansmission line, inserting a thin film attenuating plate therein and transmitting the light having been intensity modulated according to the movement of the thin film attenuating plate. CONSTITUTION:The light signal emitted from a light source 1 is led to a thin film attenuating plate 5 by an optical fiber 2. The thin film attenuating plate 5 when moved in the fixed direction is capable of monotonusly attenuating the light signal continuously. The light signal having passed through the thin film attenuating plate 5 and having undergone intensity modulation according to the movement of the thin film attenuating plate 5 is further transmitted to a remote place by the optical fiber 2 and is inputted to a light-electricity converter 3. The light-electricity converter 3 faithfully converts the light intensity signal to an electric signal and outputs the same to a signal line 4. |
