Abstract: Consistent with the present invention, tunable demultiplexers are provided in WSS-based add/drop multiplexer. The tunable demultiplexers are modular and thus allow the add/drop multiplexer to be readily expandable, and facilitate flexible add/drop capabilities whereby a channel present on any input line to the WSS can be dropped and supplied to one or more desired outputs of the tunable demultiplexer. Similar flexibility can be achieved on the add-side of the WSS. Moreover, the demultiplexers and the WSS are remotely configurable, thus obviating the need to manually disconnect and connect demultiplexers to a router. In a particular embodiment, multicast switches are provided that permit the same channel, for example, to be provided to one or more outputs of the add/drop multiplexer, such that copy of the channel can carry working traffic while the other copy carries protection traffic. As a result, 1+1 and 1:N optical layer protection can be achieved.

Abstract: Consistent with the present invention, tunable demultiplexers are provided in WSS-based add/drop multiplexer. The tunable demultiplexers are modular and thus allow the add/drop multiplexer to be readily expandable, and facilitate flexible add/drop capabilities whereby a channel present on any input line to the WSS can be dropped and supplied to one or more desired outputs of the tunable demultiplexer. Similar flexibility can be achieved on the add-side of the WSS. Moreover, the demultiplexers and the WSS are remotely configurable, thus obviating the need to manually disconnect and connect demultiplexers to a router. In a particular embodiment, multicast switches are provided that permit the same channel, for example, to be provided to one or more outputs of the add/drop multiplexer, such that copy of the channel can carry working traffic while the other copy carries protection traffic. As a result, 1+1 and 1:N optical layer protection can be achieved.

Abstract: Consistent with the present invention, tunable demultiplexers are provided in WSS-based add/drop multiplexer. The tunable demultiplexers are modular and thus allow the add/drop multiplexer to be readily expandable, and facilitate flexible add/drop capabilities whereby a channel present on any input line to the WSS can be dropped and supplied to one or more desired outputs of the tunable demultiplexer. Similar flexibility can be achieved on the add-side of the WSS. Moreover, the demultiplexers and the WSS are remotely configurable, thus obviating the need to manually disconnect and connect demultiplexers to a router. In a particular embodiment, multicast switches are provided that permit the same channel, for example, to be provided to one or more outputs of the add/drop multiplexer, such that copy of the channel can carry working traffic while the other copy carries protection traffic. As a result, 1+1 and 1:N optical layer protection can be achieved.

Abstract: A method and system for allocating bandwidth in a communication network is disclosed. Processing a request for bandwidth includes evaluating potential paths. Configuration rules and propagation rules may be applied to eliminate non-viable paths. A path quality indicator for remaining paths is derived based on calculations and signal characteristic measurements. A path having a suitable path quality indicator is selected and may be validated using existing representative or new signals.

Abstract: Optical bypass node upgrade configurations are disclosed: (1) a configuration where optical taps are pre-positioned in wavelength division multiplex (WDM) line systems terminating at optical-electrical-optical (OEO) core switching nodes to allow for future upgrade of the nodes to degree-two or higher optical bypass; (2) a configuration where the taps are pre-positioned in a degree-two optical bypass node to allow for future upgrade to a degree-N optical bypass node; and (3) a configuration and procedure for upgrading OEO core switching nodes to optical bypass when the taps have not been pre-positioned in the WDM line systems. These configurations do not introduce bit errors for non-upgraded optical paths.

Abstract: Consistent with the present invention, tunable demultiplexers are provided in WSS-based add/drop multiplexer. The tunable demultiplexers are modular and thus allow the add/drop multiplexer to be readily expandable, and facilitate flexible add/drop capabilities whereby a channel present on any input line to the WSS can be dropped and supplied to one or more desired outputs of the tunable demultiplexer. Similar flexibility can be achieved on the add-side of the WSS. Moreover, the demultiplexers and the WSS are remotely configurable, thus obviating the need to manually disconnect and connect demultiplexers to a router. In a particular embodiment, multicast switches are provided that permit the same channel, for example, to be provided to one or more outputs of the add/drop multiplexer, such that copy of the channel can carry working traffic while the other copy carries protection traffic. As a result, 1+1 and 1:N optical layer protection can be achieved.

Abstract: Consistent with the present invention, tunable demultiplexers are provided in WSS-based add/drop multiplexer. The tunable demultiplexers are modular and thus allow the add/drop multiplexer to be readily expandable, and facilitate flexible add/drop capabilities whereby a channel present on any input line to the WSS can be dropped and supplied to one or more desired outputs of the tunable demultiplexer. Similar flexibility can be achieved on the add-side of the WSS. Moreover, the demultiplexers and the WSS are remotely configurable, thus obviating the need to manually disconnect and connect demultiplexers to a router. In a particular embodiment, multicast switches are provided that permit the same channel, for example, to be provided to one or more outputs of the add/drop multiplexer, such that copy of the channel can carry working traffic while the other copy carries protection traffic. As a result, 1+1 and 1:N optical layer protection can be achieved.

Abstract: An optical communication device, and related method, are provided for providing a tailored, spectrally non-uniform gain over a broad spectrum. In particular, the optical communication device includes an optical amplifier having a dynamic gain equalization (DGE) circuit that adjusts the gain spectrum of the optical amplifier to provide uniform gain, at a desired level, within individual channel bands in accordance with the data rates of channels in those bands. Accordingly, the overall spectrum has a “stepped” profile with higher gain values for high data rate channels and lower gain values for lower rate channels. As a result, a WDM system can accommodate multiple data rate signals by providing spectrally uniform high gain for high data rate channels, and low gain for lower rate channels. Improved signal quality can thus be achieved for both high speed and low speed signals in a single WDM system.

Abstract: An infrared laser has a seed laser with an optical seed output. A pump amplifier receives the optical seed output and has an amplified output. A molecular gas laser receives the amplified output and has an infrared optical output.

Abstract: An optical communication device, and related method, are provided for reducing ripple in WDM systems. In particular, the optical communication device includes a dynamic gain equalization (DGE) circuit is coupled to an optical communication path carrying the WDM optical signals. The DGE circuit adjusts the powers associated with each channel on a channel-by-channel basis so that the WDM optical signal has a desired power spectrum. The DGE is controlled in response to sense signals generated by an optical performance monitoring (OPM) circuit located downstream from the DGE or substantially co-located with the DGE. The OPM monitors the WDM spectrum for optical signal power variations and outputs the sense signal when the variations fall outside a given tolerance. Typically, one DGE is associated with a group of concatenated amplifiers so that multiple DGEs are provided in a system having many groups of such amplifiers.