Optical transmission system including optical repeaters with selectively enabled gain equalizers contained therein and including an add/drop apparatus with a plurality of individually selectable filters

摘要

An optical transmission system including a plurality of optical repeaters arranged along a transmission line. An add/drop apparatus is also provided for adding/dropping an individual wavelength signal from a wavelength division multiplexed (WDM) signal travelling through the optical communication system. The add/drop apparatus includes a plurality of filters, and a selection mechanism. Each filter affects a different wavelength. The plurality of filters includes at least one filter affecting a wavelength corresponding to a wavelength signal in the WDM signal. The selection mechanism selects a respective filter of the at least one filter to allow the apparatus to add/drop the wavelength signal in the WDM signal corresponding to the wavelength of the selected filter.