Abstract: An optical system with a first and second network tiers. The first network tier includes a plurality of major nodes optically interconnected by at least one transmission path. The second network tier includes a plurality of minor nodes disposed along the transmission path and the minor nodes are connected to at least one of the major nodes. The minor node is configured to transmit all traffic to an adjacent major node, and the major nodes are configured to transmit to and receive information from other major nodes and minor nodes on transmission paths connected to the major node.

Abstract: An optical system with a first and second network tiers. The first network tier includes a plurality of major nodes optically interconnected by at least one transmission path. The second network tier includes a plurality of minor nodes disposed along the transmission path and the minor nodes are connected to at least one of the major nodes. The minor node is configured to transmit all traffic to an adjacent major node, and the major nodes are configured to transmit to and receive information from other major nodes and minor nodes on transmission paths connected to the major node.

Abstract: Optical communications systems including grooming, protection, restoration, and migration on a unified network platform, and using a unified control plane. The systems may include combinations of optical bypass and mesh restoration, may include combinations of shared mesh and dedicate protection, and may be combinations of long haul, extended long haul, and ultra long haul systems. The systems may also include a configurable DWDM tier to accommodate dynamic traffic patterns, thereby allowing for increased operational flexibility.

Abstract: Optical communications systems including grooming, protection, restoration, and migration on a unified network platform, and using a unified control plane. The systems may include combinations of optical bypass and mesh restoration, may include combinations of shared mesh and dedicate protection, and may be combinations of long haul, extended long haul, and ultra long haul systems. The systems may also include a configurable DWDM tier to accommodate dynamic traffic patterns, thereby allowing for increased operational flexibility.

Abstract: A method and apparatus for estimating fiber dispersion in an optical communication system including transmitting an optical signal carrying a unique word along an optical communication path, receiving the optical signal carrying the unique word from the optical communication path, producing an electrical signal corresponding to the received unique word, and processing the electrical signal corresponding to the received unique word to produce an estimate of the fiber dispersion in the optical communication system.

Abstract: Methods, systems, and devices utilizing port dimensioning strategies for supporting, for example, bandwidth-on-demand (“BoD”) services in networks. At a given node, the traffic load consists of several components, such as an access component, which is generated by demands terminated at that node, and a transit component, which is generated by demands that transit electronically through the node. Given the BoD load at a node, as well as a target BoD average blocking probability, a desired static allocation of the ports is provided between ports of a first type (such as client-side ports) and ports of a second type (such as network-side ports). In addition, a dynamic sharing strategy of the ports is also disclosed.

Abstract: A method of receiving optical channels including providing an optical band filter configured to filter at least one optical channel from a multiple channel optical signal and provide a band filtered optical signal. A periodic filter is configured to filter and/or shape one channel from the band filtered optical signal and provide the periodic filtered, shaped signal to a receiver and other optical system. The invention also relates to corresponding systems and apparatuses.

Abstract: Optical transmission systems of the present invention include optical protection systems, apparatuses, and methods that provide increased reliability in the system. The optical system generally includes an optical switch having distinct, cooperating dedicated and shared protection sections. The shared protection sections in a plurality of nodes can be configured to provide a protection net, in which a plurality of traffic demands, or working channels, are commonly protected as protection group using one protection channels supported by the protection net.

Abstract: A device and method for reducing amplified Rayleigh backscatter at a Raman pump. A pump assembly for an optical amplifier includes a set of pump radiation sources for Raman pumping an optical transmission span. Each pump radiation source is adapted to produce radiation having a pump wavelength and a pump power. The optical transmission span is adapted to provide Raman amplification of an optical data signal when pumped by the set of pump radiation sources. At least one optical isolator is selectively located between at least one selected pump radiation source and the optical transmission span to reduce amplified Rayleigh backscatter at the pump wavelength of the selected pump radiation source from feeding back into the selected at least one pump radiation source.

Abstract: A method for transmitting traffic in an optical communication system comprising separating the input traffic into a plurality of data signals, parameter encoding the data signals, transmitting each of the data signals on a separate optical channel, receiving the data signals on the channels, parameter decoding the data signals, and combining the plurality of data signals from the channels into output traffic corresponding to the input traffic.

Abstract: An optical communications system, comprising a first node, first dispersion compensation fiber located in the first node, wherein the first dispersion compensation fiber induces dispersion onto optical signals passing through the first dispersion compensation fiber, a second node, a plurality of spans between the first and second nodes, and second dispersion compensation fiber located in at least one of the spans, wherein the second dispersion compensation fiber induces dispersion onto optical signals passing through the second dispersion compensation fiber, and wherein the dispersion induced by the second dispersion compensation fiber is opposite in sign to that induced by the first dispersion compensation fiber.

Abstract: Optical systems of the present invention include first and second optical amplifiers that are operated individually to provide gain profiles that do not conform with a desired composite, or overall or total, gain profile, e.g., substantially flat, but to produce a desired composite noise figure profile, e.g., substantially flat or otherwise, for the amplifiers. Generally, the desired composite noise figure profile is produced, while attempting to minimize the deviation of the composite gain profile from the desired composite gain profile.

Abstract: Optical transmission systems including a plurality of optical amplifiers configured to provide optical amplification of one or more information carrying optical signal wavelengths. At least two of the optical amplifiers are operated to provide net losses or net gains along corresponding spans, while the cumulative gain provided by the plurality of optical amplifiers substantially compensates for the cumulative loss of the spans.

Abstract: Optical transmission systems including a plurality of optical amplifiers configured to provide optical amplification of one or more information carrying optical signal wavelengths. At least two of the optical amplifiers are operated to provide net losses or net gains along corresponding spans, while the cumulative gain provided by the plurality of optical amplifiers substantially compensates for the cumulative loss of the spans.

Abstract: A method of transmitting an optical communications signal, comprising receiving a first signal, encoding the signal with a differential or duobinary encoding scheme, encoding the signal with an oscillating signal component, and sub-carrier modulating the signal onto a sub-carrier of an optical carrier signal. The invention also relates to corresponding systems and apparatuses.

Abstract: Systems, apparatuses, and methods for producing and utilizing orthogonal optical data signals, which can be produced by modulating electrical data signals onto orthogonal polarization components of an optical carrier traveling in opposite directions in a common modulator. The modulator can include one or more traveling wave electrodes having first and second ends with a first electrical data input connected to the first end and a second electrical data input connected to the second end.

Abstract: Methods, apparatuses, and systems for encoding information symbols comprising loading information symbols into a data array with n(1) rows and n(2) columns, wherein each column has ki(1) information symbols, and wherein k(1) is an array that has at least two different values, encoding each column with a code Ci(1) from a family of nested codes C(1), wherein C(1) includes two different nested codes, and encoding each row with a code C(2).

Abstract: An optical asynchronous chirp device having an input port and an output port, comprising first and second optical phase modulators optically connected in series between the input port and the output port of the device, a local oscillator connected to the first and second phase modulators, and a phase shifter connected between the local oscillator and one of the phase modulators, and systems and methods related thereto.

Abstract: An optical communications system including a submarine optical communications system, a landing station associated with the submarine optical communications system, a terrestrial optical communications system, a point of presence associated with the terrestrial optical communications system, a first wavelength division multiplexed optical connection between the point of presence and the landing station, and a second wavelength division multiplexed optical connection between the point of presence and the landing station and routed diversely from the first wavelength division multiplexed optical connection.

Abstract: Optical systems of the present invention generally include an optical signal controller disposed along an optical link between two optical nodes. The optical signal controller is configured to provide a monitoring signal from an optical signal passing between the nodes as a plurality of wavelength sub-bands at least one of which includes a plurality of signal channels. The controller generates a compensating channel having an optical power that is a function of the monitoring signal power in the plurality of wavelength sub-bands or total power. The compensating channel is combined with the optical signal to compensate for power variations in the optical signal passing between the nodes. In addition, the compensating channels can be used to transmit communication or system supervisory information between monitoring points and/or nodes in the system.