Design of a digitally tunable optical filter system for wavelength selective switching based optical networks

What is believed to be a novel design of a digitally tunable optical filter system for wavelength-selective-switching-based optical networks is demonstrated. It uses two-by-two wavelength-selection elements and semiconductor optical amplifiers. The system can be expanded to provide selection of more channels by simply inserting one additional semiconductor optical amplifier for every new set of four channels and one wavelength-selection element per channel.