Abstract: A system for fault recovery in an optical network may include an initial loading equipment (ILE) apparatus configured to supply power to a set of channels over a first communications link of the optical network, the set of channels including data channels and spare channels, and a control system configured to detect an optical power level over the data channels of the first communications link and determine whether a Q-factor corresponding to the data channels of the first communications link is below an error correction threshold, the control system configured to alert the ILE apparatus to adjust its optical power output over the spare channels upwardly based on the determination that the Q-factor is below the error correction threshold to increase the Q-factor.

Abstract: A system for fault recovery in an optical network may include an initial loading equipment (ILE) apparatus configured to supply power to a set of channels over a first communications link of the optical network, the set of channels including data channels and spare channels, and a control system configured to detect an optical power level over the data channels of the first communications link and determine whether a Q-factor corresponding to the data channels of the first communications link is below an error correction threshold, the control system configured to alert the ILE apparatus to adjust its optical power output over the spare channels upwardly based on the determination that the Q-factor is below the error correction threshold to increase the Q-factor.

Abstract: A method of managing fault recovery in a trunk-branched OADM network may include determining that an optical power level over data channels of a first communications link between a first and a second terminal of the branched optical network exceeds an optical power limit. The method may further include increasing optical power sent over spare channels of the first communications link to a first level at which the optical power level over the data channels decreases to a second level below the optical power limit.

Abstract: An optical communication system supporting detection and communication networks. A communication network transmission path and the detection network transmission path are provided as separate paths established by separate fibers or fiber pairs of the same optical fiber cable. All of the elements coupled to the communication network transmission path and the detection network transmission path may be powered by the same power feed equipment through the same optical fiber cable power conductor.

Abstract: An optical add/drop multiplexer (OADM) and system incorporating the same for maintaining loading of WDM channels with loading signals or information signals when signals are added or dropped. The OADM may include reconfigurable band pass filters having a transmittance characteristic controllable using a command signal. Selective filtering of loading signals and/or information signals received from branch and trunk paths allows an output WDM signal including information signals on utilized channels and loading signals on all unutilized channels.

Abstract: An inverse multiplexing communication path is established in at least one direction between nodes connected by a plurality of lower bandwidth bearing channels between the nodes, on which the content of a higher bandwidth signal is distributed and from which the original high bandwidth signal is recovered at the receiving node. During preliminary configuration, for example when selecting a subset of bearer channels from among a number of potential bearer channels, the bearer channels are chosen or are altered by signal processing to make the members of the subset perform similarly, thereby improving operations as compared to having the bearer channels bound to perform according to the performance of the least-performing member of the subset.

Abstract: An optical add-drop network and wavelength allocation for the same wherein the system bandwidth is separated into a dedicated channel band and re-used channel bands, separated by guard bands, to allocate terminal connections to achieve a minimum number of re-used channel bands for the desired terminal connectivities.

Abstract: A method of managing fault recovery in a trunk-branched OADM network may include determining that an optical power level over data channels of a first communications link between a first and a second terminal of the branched optical network exceeds an optical power limit. The method may further include increasing optical power sent over spare channels of the first communications link to a first level at which the optical power level over the data channels decreases to a second level below the optical power limit.

Abstract: An undersea repeaterless optical transmission system is disclosed including first and second stations connected by a communication link which may comprise one or more optical fibers. The system further includes a dedicated Raman pumping path originating from a third intermediate station and interacting with the communication link at an undersea body positioned between the first and second stations. This dedicated Raman pumping path may comprise one or more optical fibers. Communications signals are propagated only between the first and second stations, while the third intermediate station provides only Raman pumping via the pumping path which is used to boost signal power in the communication link between the first and second stations. By limiting this pumping path to Raman pumping only substantially more pumping power can be provided through the path since power is not limited by the equation of a communications signal.

Abstract: Briefly, in accordance with one or more embodiments, a band of signal carriers is divided into a first band of carriers and a second band of carriers. The carriers in the first band comprise shorter wavelength carriers, and carriers in the second band comprise longer wavelength carriers. Each of the optical sources in the first and second bands of carriers are modulated with an input signal and coupled together via a polarization maintaining coupler. These signals are then combined via a polarization beam combiner wherein the first band has a polarization state that is orthogonal, or nearly orthogonal, to a polarization of the second state.

Abstract: An inverse multiplexing communication path is established in at least one direction between nodes connected by a plurality of lower bandwidth bearing channels between the nodes, on which the content of a higher bandwidth signal is distributed and from which the original high bandwidth signal is recovered at the receiving node. During preliminary configuration, for example when selecting a subset of bearer channels from among a number of potential bearer channels, the bearer channels are chosen or are altered by signal processing to make the members of the subset perform similarly, thereby improving operations as compared to having the bearer channels bound to perform according to the performance of the least-performing member of the subset.

Abstract: An optical add-drop network and wavelength allocation for the same wherein the system bandwidth is separated into a dedicated channel band and re-used channel bands, separated by guard bands, to allocate terminal connections to achieve a minimum number of re-used channel bands for the desired terminal connectivities.

Abstract: Dispersion may be managed in an optical network configured to transmit differential phase shift keying (DPSK) modulated signals by allowing accumulation of dispersion to thousands of ps/nm before compensating. A dispersion map providing a negative average dispersion and a minimum dispersion wavelength outside of the signal band may be employed.

Abstract: An optical add/drop multiplexer (OADM) and system incorporating the same for maintaining loading of WDM channels with loading signals or information signals when signals are added or dropped. The OADM may include reconfigurable band pass filters having a transmittance characteristic controllable using a command signal. Selective filtering of loading signals and/or information signals received from branch and trunk paths allows an output WDM signal including information signals on utilized channels and loading signals on all unutilized channels.

Abstract: An optical communication system supporting detection and communication networks. A communication network transmission path and the detection network transmission path are provided as separate paths established by separate fibers or fiber pairs of the same optical fiber cable. All of the elements coupled to the communication network transmission path and the detection network transmission path may be powered by the same power feed equipment through the same optical fiber cable power conductor.

Abstract: An apparatus and method directed to testing and optimizing performance of an optical transmission system is disclosed, including at least one broadband dispersion compensation unit (DCU) or at least one depolarization device. The depolarization device may be used alone or in combination with the at least one broadband DCU. A method for optimizing performance of data channels in initial loading (IL) and full loading (FL) configurations of the optical transmission system is also disclosed.

Abstract: A communication system including a repeatered trunk path and one or more unrepeatered branch segments coupled to the trunk path through associated submarine branching units. Each of the branch segments may be configured to carry at least the same channel capacity as the trunk path and may have a length greater than the average repeater spacing in the trunk path.

Abstract: An apparatus and method directed to testing and optimizing performance of an optical transmission system is disclosed, including at least one broadband dispersion compensation unit (DCU) or at least one depolarization device. The depolarization device may be used alone or in combination with the at least one broadband DCU. A method for optimizing performance of data channels in initial loading (IL) and full loading (FL) configurations of the optical transmission system is also disclosed.

Abstract: An apparatus and method directed to testing and optimizing performance of an optical transmission system is disclosed, including at least one broadband dispersion compensation unit (DCU) or at least one depolarization device. The depolarization device may be used alone or in combination with the at least one broadband DCU. A method for optimizing performance of data channels in initial loading (IL) and full loading (FL) configurations of the optical transmission system is also disclosed.

Abstract: Dispersion may be managed in a branched optical network by using transmission segments having a single period segment dispersion map. One or more of such segments may be coupled to network nodes such as terminals or branching units such that dispersion may be managed even when the network is reconfigured. In one embodiment, a single period segment dispersion map provides dispersion compensation at the ends of the segment. In another embodiment, a single period segment dispersion-map provides dispersion compensation at the middle of the segment.