Abstract: A pressure vessel is provided for use in an undersea environment. The pressure vessel including a pressure housing and at least two cable receiving elements disposed on opposing ends of the pressure housing for respectively receiving ends of optical cables that each include an electrical conductor therein, said cable receiving elements adapted to be in electrical contact with the respective electrical conductors in the optical cables. At least one optical amplifier is located in the pressure vessel. The optical amplifier includes at least one electrical component adapted to receive electrical power from the electrical conductors in the optical cables. The pressure vessel also includes an electrically insulating element electrically isolating at least one of the cable receiving elements from the pressure housing.

Abstract: A branching unit is provided for interconnecting at least three undersea optical transmission cables. The branching unit includes first, second and third ports for receiving first, second and third undersea optical transmission cables, respectively. The first and second cables each include an electrical power conductor and a plurality of first optical fibers. The third cable is electrically unpowered and includes at least one drop optical fiber and at least one add optical fiber. An electrical power conductor segment is provided for electrically coupling the conductor in the first cable received in the first port to the conductor in the second cable received in the second port. A first optical fiber segment optically couples a first of the plurality of first optical fibers in one of the first or second cables to the drop optical fiber of the third cable.

Abstract: An optical repeater is provided that includes at least four optical amplifiers each supplying optical amplification to an optical signal traveling in a different unidirectional optical fiber that collectively form at least two bi-directional pairs of optical fibers. The repeater also includes a first plurality of pump sources for providing pump energy to a first optical fiber located in a first of the optical fiber pairs and a second optical fiber located in a second of the optical fiber pairs. The first optical fiber and the second optical fiber support optical signals traveling in a common direction. A first combiner arrangement combines the pump energy from the first plurality of pump sources and distributes it to the optical amplifiers supplying amplification to optical signals traveling in the first and the second optical fibers.

Abstract: An optical amplifier module is provided that contains at least one optical amplifier. The module includes an internal housing having an outer dimension substantially equal to an outer dimension of an internal fiber splice housing of an undersea optical fiber cable joint. The internal housing includes a pair of opposing end faces each having a retaining element for retaining the internal housing within an outer housing of the undersea optical fiber cable joint. The internal housing also includes a sidewall interconnecting the opposing end faces, which extends between the opposing end faces in a longitudinal direction. The sidewall includes a receptacle portion having a plurality of thru-holes each being sized to receive a passive optical component employed in an optical amplifier. The module also includes at least one circuit board on which reside electronics associated with the optical amplifier.

Abstract: An optical amplifier module contains at least one optical amplifier. The module includes an internal housing having an outer dimension substantially equal to an outer dimension of an internal fiber splice housing of an undersea optical fiber cable joint. The internal housing includes a pair of opposing end faces each having a retaining element for retaining the internal housing within an outer housing of the undersea optical fiber cable joint. The internal housing also includes a sidewall interconnecting the opposing end faces, which extends between the opposing end faces in a longitudinal direction. The sidewall includes a receptacle portion having a plurality of thru-holes each being sized to receive a passive optical component employed in an optical amplifier.

Abstract: A method and apparatus is provided for using optical time-domain reflectometry (OTDR) with a WDM transmission system that includes a plurality of terminals interconnected by at least two pairs of unidirectional optical transmission paths each of which has at least one repeater therein. The method begins by transmitting an optical probe signal from a first OTDR unit associated with a first terminal into the repeater over a first optical path in a first of the at least two pairs of unidirectional optical transmission paths. The first OTDR unit receives a first returned OTDR signal over a second optical path in the first optical path pair. The first OTDR signal contains status information concerning the first optical path in the first optical path pair. The optical probe signal from the first optical path in the first optical path pair is coupled to a second optical path in the second optical path pair.

Abstract: An optical amplifier module contains at least one optical amplifier. The module includes an internal housing having an outer dimension substantially equal to an outer dimension of an internal fiber splice housing of an undersea optical fiber cable joint. The internal housing includes a pair of opposing end faces each having a retaining element for retaining the internal housing within an outer housing of the undersea optical fiber cable joint. The internal housing also includes a sidewall interconnecting the opposing end faces, which extends between the opposing end faces in a longitudinal direction. The sidewall includes a receptacle portion having a plurality of thru-holes each being sized to receive a passive optical component employed in an optical amplifier.

Abstract: A method and apparatus is provided for using optical time-domain reflectometry (OTDR) with a WDM transmission system that includes a plurality of terminals interconnected by at least two pairs of unidirectional optical transmission paths each of which has at least one repeater therein. The method begins by transmitting an optical probe signal from a first OTDR unit associated with a first terminal into the repeater over a first optical path in a first of the at least two pairs of unidirectional optical transmission paths. The first OTDR unit receives a first returned OTDR signal over a second optical path in the first optical path pair. The first OTDR signal contains status information concerning the first optical path in the first optical path pair. The optical probe signal from the first optical path in the first optical path pair is coupled to a second optical path in the second optical path pair.

Abstract: An optical transmission system includes a transmitter unit, a receiver unit, and an optical transmission path interconnecting the transmitter and receiver units. A plurality of optical repeaters are situated along the transmission path. Adjacent ones of the repeaters are interconnected by transmission spans that collectively constitute a majority of the optical transmission path. Each of the transmission spans comprises substantially identical lengths of cabled optical fiber having substantially identical prescribed path average dispersions. At least one adjustable dispersion trimming element is located in the optical repeater and optically couples one of the transmission spans to an optical amplifier located in the repeater. The adjustable dispersion trimming element has an adjustable path average dispersion selected such that a total path average dispersion of the transmission span to which it is coupled plus the adjustable dispersion trimming element has a desired value.

Abstract: A test system is provided for monitoring a WDM transmission system that employs at least one optical amplifier. The test system includes a test signal generator generating an optical test signal and an optical coupler combining the test signal with at least one data signal located at a given channel wavelength. The optical test signal is located at one or more channel wavelengths distinct from the given channel wavelength and which corresponds to an idler channel wavelength that is employed to maintain a prescribed operational state of the optical amplifier. The test system also includes an optical performance monitor receiving at least a portion of the optical test signal.

Abstract: A method is provided for using OTDR with a bi-directional optical transmission system that includes first and second terminals interconnected by at least first and second unidirectional optical transmission paths having at least one repeater therein. The method begins by transmitting optical probe signals over the first optical path and receiving over the second optical path returned OTDR signals in which status information concerning the first optical path is embodied. The optical probe signals and the returned OTDR signals are transmitted and received, respectively, at time intervals allowing individual spans of the first optical path, which are separated by the repeater or repeaters, to be monitored in a sequential manner.