Patent ID: 7619812

Claim:
A method for a rapid tilt adjustment of a wavelength multiplex signal transmitted over a fiber optical waveguide, the method comprising: measuring the tilt and/or a level of the wavelength multiplex signal at an output of the fiber optical waveguide; generating at least one tilt correction pump signal having a frequency outside a used transmission band; controlling the power of the tilt correction pump signal according to the measured tilt and/or level of the wavelength multiplex signal; injecting the at least one tilt correction pump signal into the fiber optical waveguide in the opposite direction of the transmission direction of the wavelength multiplex signal; generating an anti-pump signal absorbing energy of the tilt correction pump signal, the anti-pump signal having a frequency deviation to the tilt correction pump signal and a power between 0.5 times and 2 times of the tilt correction pump signal; and injecting the anti-pump signal into the fiber optical waveguide in the opposite direction of the transmission direction of the wavelength multiplex signal.