| 摘要 |
The present invention provides a reconfigurable optical add-drop multiplexes for a wavelength division multiplexed optical communication system. The recon- figurable add-drop multiplexes includes a static optical add-drop multiplexes including an input port for receiv- ing optical signals from an optical transmission path in a wavelength division multiplexed optical communica- tion system, a drop port for routing optical channels to be removed from an optical transmission path, and add port for receiving optical channels to be added to an optical transmission path, and wavelength selecting means for selecting optical channels to be dropped from the optical transmission path. An optical path com- municates with the drop port, which includes an op- tical demultiplexer having an input port for receiving the dropped optical channels and plural demultiplexer output ports for separately outputting optical channels. Plural demultiplexer optical paths optically communi- cate with the optical demultiplexer for receiving each of the dropped optical channels. Similarly, an optical path optically communicates with the add port of the static add-drop multiplexer. The add optical path includes an optical combiner having plural combiner input ports communicating with plural combiner optical paths for receiving optical channels to be added to the optical transmission path and an output port for outputting a combined optical signal comprising the optical channel s received from the combiner input ports. An optical switch is positioned in one or more of the demultiplexer optical paths, which permi ts switching of a dropped optical channel between a receiver optical path for directing the dropped optical signal to an optical receiver and between a combiner optical path for routing the dropped optical channel back towards the optical transmission path optionally passing the dropped optical channel through a remodulator. Alternatively, the optical switch routes the dropped optical channel towards an optical receiver while permitting a new optical channel to be routed to add port of the static add-drop multiplexer.
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