Optical repeater comprising a Raman amplifier

摘要

Embodiments of the present invention relate to an optical repeater and a method for Raman-amplifying a signal light. The optical repeater comprises a rare-earth doped fiber amplifiers (10), with substantially fixed amplifying gain characteristics, having a first amplifying optical fiber including rare-earth doped optical fiber; a Raman amplifier (9), which has a second amplifying optical fiber and pumping units (1) for supplying pumping light having one or more central wavelengths to the second amplifying optical fiber, connected to a front stage of the rare-earth doped fiber amplifiers, the Raman amplifier being configured to have a variable gain profile by controlling intensity of the pumping light outputted from the pumping unit; and a controlling unit (15, 24) for controlling the intensity of the output light which is to be outputted to the rare-earth doped fiber amplifier by compensating for fluctuation of intensity in the input light being inputted to the Raman amplifier by controlling the gain profile of the Raman amplifier.