A pumping source is provided for the Raman amplification of an optical
wavelength division multiplex signal, wherein the pumping source has a
number of pumping lasers with, in each case, different pumping
wavelengths. Modules for the angle and/or amplitude modulation of pumping
signals of the pumping lasers are connected to the pumping lasers, such
that by appropriate adaptation of the modulation of the pumping signals
mixing products from four-wave mixing between the pumping signals are
suppressed.
