Channel skip filters are components added to wavelength division multiplexing (WDM) add/drop modules — in both coarse wavelength division multiplexing (CWDM) and dense wavelength division multiplexing (DWDM) applications — to facilitate band splitting and to manage multiple ITU channels.
These filters feature narrow transitions from pass band to blocking band, minimizing lost channels while maintaining high spectral efficiency (i.e., limiting insertion loss) since the express channels undergo only one reflection.