Optical transmission link incorporating highpass optical filtering

摘要

An optical fiber transmission link with reduced channel depletion due to stimulated Raman scattering is formed by including a high pass optical filter in the transmission fiber. The filter may comprise one or more discrete components, or may be formed as a "distributed" filter along the length of the optical fiber. The cut-off frequency for the high pass optical filter is selected to be immediately below the frequency of the input channel to be transmitted. When used in an arrangement with multiple input channels, the cut-off frequency is controlled to be immediately below the lowest input channel frequency.