| 摘要 |
PURPOSE:To constitute a system immune from the environment with a low cost by providing an optical modulator in place of a light emitting element to one line in a 2-wire optical transmission system. CONSTITUTION:The light emitting element 1 converts an electric signal (a) from the side A to the side B into an optical signal and sends an optical signal to an optical fiber 5. The optical signal through the optical fiber 5 is branched by a demultiplexer 2, a part is given to a light receiving element 3 and the remaining signal is given to an optical switch 4. The optical signal branched by the demultiplexer device 2 is modulated by the optical switch 4 by using an electric signal (b) and sent from the side B to the side A through the optical fiber 5 and converted into the electric signal by a light receiving element 7. |
