| 摘要 |
PURPOSE:To decrease the scale of a circuit and to reduce the deterioration of transmission by using the optical wavelength multiplex transmission technology, transmitting all signals at each terminal device or service unit while using a light source of different wavelength and separating the wavelength at a transmitter at the station side and a transmitter at the subscriber. CONSTITUTION:Electric signals from terminal devices 11-1n are converted into optical signals by electrooptic converting circuits 71-7n, the optical signals are coupled to an optical fiber 9' by an optical synthesizer and branching filter 8 through optical fibers 911-9n1 and transmitted. The optical signal through the optical fiber is extracted by the optical synthesizing and branching filter 8', converted into electric signals by an optoelectric converting circuit 10' and inputted to an intra-office transmitter or exchanges 131-13n . On the other hand, the signal outputted from the intra-office transmitter or the exchanges 131-13n is transmitted to the terminal device through the opposite path to the path above. Since the wavelength of the light source of the electroptic converting circuits 71-7n, 71'- 7n' is different entirely, the wavelength of the signals is synthesized or separated by the optical synthesizer and branching filter and transmitted through one optical fiber 9'. |
