OPTICAL TRANSMISSION SYSTEM, OPTICAL TRANSMITTER AND RECEIVER

PROBLEM TO BE SOLVED: To provide an optical transmission system exhibiting excellent maintainability by simplifying the arrangement, and to provide its optical transmitter and receiver. SOLUTION: In the optical transmission system for transmitting an optical signal subjected to intensity modulation with a radio frequency signal bidirectionally, the optical signal in up-link is pulsated intermittently when it is required to transfer an alarm from a slave station device 20 to a mater station device 10. More specifically, when a fault is detected on the transmission side, emission/nonemission of the optical signal is repeated intermittently. On the reception side, instantaneous value and integrated value of light reception level of the optical signal are monitored and generation of an alarm is detected by the edge of a pulse waveform shown by the light reception level. COPYRIGHT: (C)2006,JPO&NCIPI