| 摘要 |
PURPOSE:To facilitate the maintenance of a transmitting terminal station by providing an optical external modulator on the transmitting terminal station, and providing a light emitting element connected to an input terminal of the optical external modulator and a light receiving element connected to an output terminal of the optical external modulator on a receiving terminal station. CONSTITUTION:In an optical signal transmission device consisting of a transmitting terminal station 2 and a receiving terminal station 1 connected to the terminal station 2 through an optical fiber cable 6, an optical external modulator 5 is provided on the terminal station 2, and a light emitting element 3 and a light receiving element 4 are provided on the terminal station 1. Also, the element 3 is connected to an input terminal of the modulator 5, and the element 14 is connected to an output terminal of the modulator 5. In such constitution, when an optical signal is sent out to the cable 6 from the element 3 of the terminal station 1, in the terminal station 2, the optical signal from the terminal station 1 is modulated in accordance with information by the modulator 5, a modulated signal is sent out to the cable 6 and the information is demodulated by the element 4 of the terminal station 1. In such a way, the maintenance of the element 3 can be executed in a lump on the terminal station 1 side together with the element 4, therefore, the maintenance and the repair of the terminal station 2 can be facilitated. |
