| 摘要 |
PURPOSE: To attain information transmission using an excited light with a different wavelength from that of a signal as a carrier on the same optical transmission line as the signal light in addition to information transmission by the signal light by modulating the excited light by a high frequency wave with a specific period. CONSTITUTION: When a transmission instruction of monitor information is received by an incoming repeater 18, a controller 46 controls a modulation circuit 48 based on outgoing monitor information from a signal processing circuit 44 to apply intensity modulation to a stimulated light from a power supply 30 for stimulated light. The modulation speed in this case is sufficiently higher than a reciprocal of a life of a fluorescent light of a rare-earth doped fiber 28, that is, the monitor information is sent as a carrier for a stimulated light almost without the modulation component in the signal light by modulating the stimulated light with a high frequency signal whose period is almost shorter than the life of the fluorescent light in the stimulated state. Thus, in addition to transmission of information by a signal light with a same transmission line, information such as monitor information is sent by using a carrier with a different wavelength from that of the signal light. |
