Patent ID: 6678080
Filing Date: 2004-01-13
Classification: G02B,H04J,H04Q

Abstract:
An optical add/drop multiplexer for a node of a telecommunications system, in which telecommunications system a main system signal is transmitted along an optical fiber using wavelength multiplexing, the main system signal including a plurality of signals having associated wavelengths, the plurality of signals being dropped and added in response to the associated wavelengths, the optical add/drop multiplexer comprising:a group including: at least two direction selective organs having at least three gates; and at least one wavelength selective organ located between two direction selective organs, the wavelength selective organs being coupled to add or drop the plurality of signals having a desired wavelength, wherein several groups are connected to one another by optically coupling at least one of the at least three gates of the direction selective organs in the group, a portion of the at least three gates of the direction selective organs being used as gates of the add/drop multiplexer, wherein the gates of the add/drop multiplexer are selected from a group consisting of a unidirectional add gate, a unidirectional drop gate and a bi-directional add/drop gate, whereby the function of the add/drop multiplexer is configurable such that those wavelengths which experience most attenuation in the network will correspondingly experience less attenuation in the optical add/drop multiplexer.