Abstract: An optical communication system transmitting a plurality of channel wavelengths is provided. The system includes a transmitter unit, a receiver unit, and an optical transmission path interconnecting the transmitter and receiver units. The transmission path has a concatonation of optical fibers defining a dispersion map such that each of the channel wavelengths are located at FMX and XPM antiresonances at which FWM and XPM are suppressed.

Abstract: An undersea optical repeater is provided. The repeater includes a pressure vessel for use in an undersea environment. The pressure vessel includes a pressure housing and at least two cable reeving elements disposed on opposing ends of the pressure housing for respectively receiving ends of optical cables that each include an electrical conductor therein. The cable receiving elements are 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 housing includes a dielectric layer having sufficient dielectric properties for electrically isolating the cable receiving elements from one another to provide a voltage thereacross.

Abstract: A method is provided for locating a fault in one or more optical amplifiers operating in saturation and located along an optical transmission path. The method begins by generating a coherent optical time domain reflectometry (COTDR) trace representing a backscattered and/or reflected optical power level along the transmission path and comparing the trace to a reference trace to generate a difference trace that represents a change in gain. The change in gain is assigned to at least one of the optical amplifiers based on the difference trace. The method comprises assigning the difference trace to faults in the optical amplifiers, equating the difference trace with a linear combination of difference trace vectors each arising from a fault in a different one of the optical amplifiers, and iterating to determine a coefficient value associated with each difference trace vector. Each nonzero coefficient value denotes a fault in an optical amplifier.

Abstract: A land-based cable station is provided for interfacing with first and second undersea transmission segments of an undersea optical transmission system. At least one first bypass optical transmission path is provided for selectively coupling reflectometry probe signals and backscattered and reflected signals located at a prescribed wavelength from a first interface device to a second interface device. At least one second bypass optical transmission path is provided for selectively coupling reflectometry probe signals and backscattered and reflected signals located at a prescribed wavelength from the second interface device to the first interface.

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 factory 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: A method is provided for using optical time-domain reflectometry (OTDR) with a bi-directional optical transmission system that includes a plurality of terminals interconnected by first and second unidirectional optical transmission paths having at least one repeater therein. The method begins by transmitting a probe signal from a first terminal through the repeater over the first optical transmission path. A returned OTDR signal is received over the first optical transmission path in which status information concerning the first optical transmission path is embodied. The returned OTDR signal is transformed to a digitized electrical signal and the digitized electrical signal is transformed to an optical data signal. Finally, the optical data signal is transmitted over the second optical transmission path to the first terminal for extracting the status information embodied therein.

Abstract: An optical and electrical isolating unit for use with a branching unit located in an undersea optical transmission system is provided. The unit includes a pressure vessel adapted for use in an undersea environment. First, second and third ports are located in the pressure vessel for receiving first, second and third undersea transmission cables, respectively. The first cable includes an electrical power conductor and at least one optical fiber. The second cable includes an electrical conductor, and the third cable, which is electrically unpowered, includes at least one 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. At least one optical fiber segment is located in the pressure vessel, which segment optically couples the optical fiber of the first cable to the optical fiber of the third cable.

Abstract: An hermetically sealed, optical fiber assembly is provided. The assembly includes a plurality of optical fibers and a ferrule. The ferrule has a first aperture extending through a first end of the ferrule and a plurality of second apertures extending through a second end of ferrule opposing the first end of the ferrule such that a continuous passage is formed between the first aperture and each of the second apertures. The first aperture, which has a diameter greater than a diameter of the second apertures, is sufficiently large in size to receive the plurality of optical fibers therein. Each of the optical fibers traverses the first aperture and a respective one of the second apertures. An adhesive material secures each of the optical fibers to the first aperture and to the respective one of the second apertures. A solder material bonds each of the optical fibers to an entrance to the respective one of the second apertures.

Abstract: An undersea optical repeater is provided that includes a pressure vessel for use in an undersea environment. The pressure vessel has at least two cable-receiving elements for respectively receiving ends of optical cables that each includes an electrical conductor therein. 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. A dielectric envelope surrounds the pressure vessel to provide a hermetic seal therewith. The envelope includes a dielectric overmold surrounding at least a portion of the pressure vessel.