Patent ID: 7676160

Claim:
A supervisory controlling method for supervising and controlling an optical repeater based on supervisory control information to be transmitted together with a signal light propagated through an optical transmission path in an optical amplifying-and-repeating transmission system for amplifying and repeatingly transmitting said signal light by said optical repeater, comprising: Raman amplifying a supervisory control signal light having a wavelength capable of being amplified based on the Raman effect in a Raman amplifying medium on said optical transmission path, the signal light acting as an excitation light for purposes of said Raman amplifying; supervising and controlling said optical repeater in accordance with said Raman amplified supervisory control signal light; when said optical transmission path includes an up-link and a down-link, at said optical repeater, separating said Raman amplified supervisory control signal light from the lights propagated through said up-link; branching the separated supervisory control signal light into two branched lights at a previously set ratio, so that one of said branched lights is returned to said up-link and the other branched light is sent to said down-link to be folded; at the same time, separating said Raman amplified supervisory control signal light from the lights propagated through said down-link; and branching the separated supervisory control signal light into two branched lights at a previously set ratio, so that one of said branched lights is returned to said down-link and the other branched light is sent to said up-link to be folded.