Method for the raman amplification of optical signals and transmission system

A method for Raman amplification of optical signals in a wavelength division multiplexing optical transmission system, the method comprising:

• transmitting optical signals within a transmission band via an optical waveguide between a transmitter and a receiver;
• Raman-amplifying the optical signals with at least one pump so as to distort an amplification profile of the Raman amplification within the transmission band;
• and
• rectifying the distorted amplification profile so as to compensate for the distortion.

A wavelength division multiplexing optical transmission system comprising:

• a transmitter;
• a receiver;
• an optical waveguide connecting the receiver to the transmitter such that optical signals are transmittable within a transmission band via the waveguide;
• at least one Raman pump having a predetermined pump frequency at the waveguide for Raman amplification of the optical signals, the predetermined pump frequency being selected to distort an amplification profile of the Raman amplification within the transmission band;
• and
• a rectifier configured to rectify the distorted amplification profile.

A method for setting up a wavelength division multiplexing optical transmission system with Raman amplification, in which optical signals are transmittable within a transmission band via an optical waveguide between a transmitter and a receiver, the method comprising:

• defining a target parameter for an average amplification for Raman amplification within the transmission band, the target parameter being correlated with one or more first pump frequencies and a non-distorted first amplification profile (VP3) being defined by the one or more first pump frequencies;
• determining one or more second pump frequencies for a second amplification profile that is distorted with respect to the first amplification profile (VP3);
• providing one or more pumps having the second pump frequency or frequencies for the Raman amplification of the signals to be transmitted;
• and
• providing a rectifier for rectifying the distorted second amplification profile such that a rectified amplification profile is generated for operating the transmission system.