Wavelength locked feedback loops are provided in frequency guide filters,
and particularly in sliding frequency guide filters, wherein the
wavelength locked feedback loop allows precise control over the location
of the filter center wavelength with respect to a transmitted soliton
center wavelength, compensating for factors such as the filter rolloff,
signal spectral width, and changes in the transmission line properties due
to temperature, microbending, aging and other effects. This approach
allows the construction of very inexpensive frequency guiding filters,
which can be based on low precision frequency domain filters with active
compensation. These advantages make it possible to design new types of
dispersion managed soliton optical transmission networks.
