| 摘要 |
PURPOSE:To make it possible to eliminate the need to provide a light emitting device except one light emitting device provided at the master terminal station of a light transmission system, by transmitting light signals from the master terminal station to a subordinate terminal station and then by receiving unmodulated light from the master terminal station by the subordinate terminal station via optical fiber. CONSTITUTION:In master terminal station 2-1, an information signal is received by photoelectric converter 3-1, a signal amplified by regenerative amplifier 4-1 is inputted to light modulator 5-1 and unmodulated light from light emitting device 6-1 is modulated and sent to optical fiber 1-1. To transmit the information signal from terminal station 2-2 to terminal station 2-1, information signal light incident to photoelectric converter 3-2 is amplified by amplifier 4-2, whose output is inputted to light modulator 5-2. On the other hand, the unmodulated light from light emitting device 7-2 in terminal station 2-1 is transmitted to light modulator 5-2 in terminal station 2-2 via fiber 7 for unmodulated light transmission and the rest of this unmodulated light is all modulated by light modulator 5-2 and sent to fiber 1-2 for information signal light transmission. |
