Wavelength division multiplex wdm optical network

摘要

A wavelength division multiplex (WDM) optical network comprises a ring configuration of optical fiber links (4a-4f) connecting a plurality of nodes (2a-2f) and add (8) and drop (10) filters at each node (2a-2f) connected in series within the ring. One or more of said (8, 10) filters are arranged to add or drop at least two selected adjacent wavelength channels (lambdaN, lambdaM) of the WDM optical signal whilst allowing the remainder of the channels within the WDM signal to pass substantially unattenuated. The wavelength channels of each node are selected such as to maximise the number of adjacent wavelength channels at each node.