Patent ID: 6980742
Filing Date: 2005-12-27
Classification: H04B

Abstract:
1. A method for controlling the wavelength of a plurality of channels launched by optical transmission means and received by at least one wavelength selective element in an optical WDM link, the method including: noting a starting value of a wavelength influencing parameter of said wavelength selective element, for each channel, determining a channel centre value (MCDn) of said parameter of said wavelength selective element at which the output power of said channel is a maximum, calculating a mean value (MD) corresponding to the average of said channel centre values (MCDn) for all channels, and utilising said mean value (MD) to determine a deviation between said launched wavelengths and wavelengths selected by said wavelength selective element indicative of wavelength drift in said optical link, and to correct said wavelength deviation at at least one of said wavelength selective element and said optical transmission means.