Pumping unit for a Raman amplifier and Raman amplifier comprising the same

摘要

Embodiments of the present invention relate to a pumping unit for a Raman amplifier (9) and to a Raman amplifier, the pumping unit comprising: a pumping light source (1,51) that includes a plurality of semiconductor lasers (3), the plurality of semiconductor lasers arranged to emit laser lights each having a different predetermined central wavelength; a plurality of external resonators (5) configured to keep the predetermined central wavelengths of the laser lights substantially constant notwithstanding fluctuation of driving currents of the plurality of semiconductor lasers; and a laser light intensity control unit (15, 24) configured to control a gain profile of the Raman amplifier by controlling intensities of the laser lights emitted from the plurality of semiconductor lasers, the predetermined central wavelengths of the laser lights being kept substantially constant by the plurality of external resonators.