The invention relates to configurable add-drop multiplexing devices and an optical wavelength division multiplex (WDM) transmission system realized with these devices.
In purely optical WDM networks, transmission channels with different wavelengths are used for establishing data connections. At the request of customers, connections between any desired connecting points are to be made available by the network operator. To establish these connections, until now electronically operating cross-connectors/connecting-through devices were used. The same principle can also be used in principle for purely optically operating networks. However, here the use of remote-configurable optical switching devices is problematical and very cost-intensive. Such devices are known for example from DE 19 94 302 A1.
U.S. Pat. No. 5,748,350 discloses optical multiplexers/demultiplexers which are realized with the aid of filters and circulators and combine individual optical channels to form a WDM signal or divide a WDM signal into individual optical channels.