Abstract: A method for generating a wavelength division multiplexed (WDM) signal to be propagated over an optical path and to optically amplified by a gain factor, the method including the step of: determining a level of input optical signals of different wavelengths to be multiplexed and sent over the optical path; generating a level correction signal, for compensating for a correlation between the gain factor and the level of the WDM signal; and multiplexing the level correction signal and the optical signals to generate the WDM signal.