DYNAMICALLY RECONFIGURABLE OPTICAL ADD-DROP MULTIPLEXERS FOR WDM OPTICAL COMMUNICATION SYSTEMS

摘要

The present invention provides a reconfigurableoptical add-drop multiplexes for a wavelength divisionmultiplexed optical communication system. The recon-figurable add-drop multiplexes includes a static opticaladd-drop multiplexes including an input port for receiv-ing optical signals from an optical transmission path ina wavelength division multiplexed optical communica-tion system, a drop port for routing optical channelsto be removed from an optical transmission path, andadd port for receiving optical channels to be added toan optical transmission path, and wavelength selectingmeans for selecting optical channels to be dropped fromthe optical transmission path. An optical path com-municates with the drop port, which includes an op-tical demultiplexer having an input port for receivingthe dropped optical channels and plural demultiplexeroutput ports for separately outputting optical channels.Plural demultiplexer optical paths optically communi-cate with the optical demultiplexer for receiving each ofthe dropped optical channels. Similarly, an optical pathoptically communicates with the add port of the staticadd-drop multiplexer. The add optical path includesan optical combiner having plural combiner input portscommunicating with plural combiner optical paths for receiving opticalchannels to be added to the optical transmission path and an outputport for outputting a combined optical signal comprising the optical channelsreceived from the combiner input ports. An optical switchis positioned in one or more of the demultiplexer optical paths, which permitsswitching of a dropped optical channel between a receiveroptical path for directing the dropped optical signal to an optical receiverand between a combiner optical path for routing the dropped opticalchannel back towards the optical transmission path optionally passing thedropped optical channel through a remodulator. Alternatively,the optical switch routes the dropped optical channel towards an opticalreceiver while permitting a new optical channel to be routed to addport of the static add-drop multiplexer.