Abstract: A method and apparatus are present for managing a transmission of photons. The number of parameters for transmitting the photons as a beam in a liquid are identified using a number of characteristics of the liquid to form a number of selected parameters. The photons are transmitted in the liquid as the beam to a target using the number of selected parameters to form the transmission of the photons.

Abstract: A WDM communication system that includes links traversing substantially inaccessible regions may tolerate multiple failures. In one implementation, a primary link spanning such a region is protected by a backup link. To provide further fault tolerance diverse paths may be provided to and from this backup link. The region may be, for example, an ocean.

Abstract: The present invention relates to a system that provides flexible data access to a wired underwater communications network through an electromagnetic, non-conductive connection. An underwater data access point is described wherein data access to a cabled network is provided through an electromagnetic connection. An inductive connector system may also be provided to allow transfer of data and/or power between a data access point and a client system.

Abstract: A subsea monitoring system.

Abstract: An underwater data transmission system including arrays of nano-meter scaled photon emitters and sensors on an outer surface of an underwater platform. For the emitters, a laser is pulsed to correlate with data packets, providing a beam of photons at a prescribed frequency. Nano-scaled collecting lenses channel the incoming photons to photo-receptors located at a focal plane for the frequency at the base of each lens. A coating on the lenses absorbs photons at the frequency that are not aligned with the longitudinal axes of the lenses or tubes. Nano-wires connect the photo-receptors to a light intensity integrator. The integrator integrates the intensity over a surface area. The output of the integrator is fed to a signal processor to track and process the arriving digital packets.

Abstract: At least two light beams with polarization diversity are generated that each carry a representation of the same information. Separate optic fibers carry each of the at least two beams through a region subject to vibration to a remote location where the information is recovered by an optical receiver based on the separate light beams. Using separate fibers to carry polarization diverse information minimizes polarization noise at the optical receiver due to vibration of the fibers.

Abstract: A multimode wireless communications system that uses the three mechanisms of light, radio and acoustic carriers either in combination or through selection of the most appropriate carrier.

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 system for signaling between elements in an undersea optical communication system including a cable signal generator. The signal generator includes line current modulation circuitry configured to impart modulation in line current provided on a power conductor of the transmission cable. A method of signaling between elements in an undersea optical communication system includes modulating a line current through an element and detecting the modulated current.

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: In each of a plurality of submarine observation apparatus (1 to n), a branching unit (63) branches fixed-wavelength light (?1) from an incoming wavelength-multiplexed light signal. An observation signal modulating unit (64) modulates the intensity of the branched fixed-wavelength light (?1) with observation information multiplexed by an observation signal multiplex unit (61). A combining unit (65) combines light signals (?2) to (?n) passing through the branching unit (63) and the fixed-wavelength light (?1a) modulated by the observation signal modulating unit (64) into a composite light signal, and outputs it to an optical fiber (12a). Therefore, in each of the plurality of submarine observation apparatus (1 to n), there is no necessity for providing a wavelength-division-multiplexing-transmission optical transmitter which requires high wavelength stability.

Abstract: A system for delivering optical signals to and from an undersea optical cable may include a cable landing station connected to the undersea optical cable and configured to convey a wavelength division multiplexed optical signal from the undersea optical cable. The system may also include a point of presence that includes wavelength division multiplexing equipment configured to convert the wavelength division multiplexed optical signal to a number of optical channels. At least one terrestrial optical fiber may be coupled between the cable landing station and the point of presence to transport the wavelength division multiplexed optical signal from the cable landing station to the point of presence.

Abstract: An underwater optical communications system and method particularly suitable for use in communications with automated equipment. A series of light beacons are dispersed throughout a communications zone. The light beacons are each provided with a plurality of light-emitting elements and light receiving elements which are positioned so that each beacon within the communications zone emits light in a plurality of directions and receives light from a plurality of directions. A submersible craft is similarly provided with light emitting elements and light receiving elements. The submersible craft is thus always in optical communication with one or more beacons when in the communications zone, regardless of the orientation of the craft and regardless of the position of the craft within the communications zone.

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: A bi-directional configuration is employed to implement a hybrid ultra long haul (ULH)/long haul (LH) optical transmission system. The link carries ULH channels and LH channels in opposite directions in different bands. Raman amplification is employed for the ULH band while Erbium-doped fiber amplification (EDFA) is used for both the LH and ULH bands. Optical circulators are employed for multiplexing and demultiplexing. This solution does not incur the ripple penalty of prior art solutions based on interferential filters while providing excellent isolation between the ULH and LH channels and bi-directional communication within a single fiber.

Abstract: A land-based cable station is provided for interfacing with first and second undersea transmission segments of an undersea optical transmission system. The cable station includes optical transmission terminal equipment for receiving and transmitting optical signals that undergo opto-electric conversion therein. A first interface device is operably coupled to the terminal equipment for bidirectionally communicating optical signals between the terminal equipment and the first undersea transmission segment and for providing signal conditioning to the optical signals received from the terminal equipment so that the optical signals are suitable for transmission through the first undersea transmission segment.

Abstract: A main line cable and a backup line cable are laid in a land portion in different routes. A land terminal station includes a break detecting unit that detects a break of the main line cable, and a path switching unit that switches a transmission path to the backup line cable. The break detecting unit detects a break of the cables based on a received-light level of a main signal transmitted from an underwater cable, or based on a received-light level of a returned monitor signal that has been output by the break detecting unit and reflected by the beach manhole. The beach manhole includes optical couplers that couple and divide the main signal for the main line cable and the backup line cable, a fiber grating that reflects the monitor signal, and an optical director.

Abstract: A branching unit for an optical transmission system, an optical transmission system and a method of operation of said branching unit (30) is disclosed having a first branch (38) and a second branch (40), each connected to a main branch (42). First directional current flow means (54) and second directional current flow means (58) are operable to allow electrical current to flow substantially in one direction only along the first branch (38) and the second branch (40) respectively such that electrical current flow from the first branch to the second branch and from the second branch to the first branch is substantially prevented and a simultaneous conduction of current between the first branch and the main branch and between the second branch and the main branch is prevented.

Abstract: The systems and methods of the invention provide for improved underwater communication systems. In particular, the systems and methods of the invention provide for improved underwater optical modems including optical transmitters and optical receivers that allow omni-directional transmission and reception of optical signals underwater and having a range of about 100 m and allowing data rates greater than 1 Mbit/s. The systems and methods of the invention also provide for underwater communication networks having a plurality of optical modems communicating with each other.

Abstract: A power feed arrangement for aggregate segments of a communications system is disclosed. In embodiments of the invention, cables are used to communicatively connect a number of landmasses, where the cables also serve to carry electrical power to devices connected along lengths of the cables. A first cable is connected to first and second landmasses, while a second cable is connected to second and third landmasses. On the second landmass, the electrical power conductors of the first and second cables are electrically connected to one another, and pieces of power feed equipment located on said first and third landmasses are used to supply electrical power to devices located along lengths of the first and second cables. Alternative embodiments are also disclosed.

Abstract: A telemetry system includes a plurality of acoustic sensors for receiving acoustic information and generating analog signals based on the received acoustic information. A first plurality of subsystems is coupled to at least a subset of the plurality of acoustic sensors. The first plurality of subsystems is configured to receive the analog signals from the acoustic sensors and generate digital values based on the received analog signals. The system includes a first optical splitter. A first optical transmitter transmits a first set of optical pulses to the first optical splitter. The first optical splitter is configured to transmit the first set of optical pulses to each subsystem in the first plurality of subsystems. Each subsystem in the first plurality of subsystems is configured to modulate the first set of optical pulses based on the generated digital values and thereby generate a modulated optical pulse stream.

Abstract: A power feed arrangement for aggregate segments of a communications system is disclosed. In embodiments of the invention, cables are used to communicatively connect a number of landmasses, where the cables also serve to carry electrical power to devices connected along lengths of the cables. A first cable is connected to first and second landmasses, while a second cable is connected to second and third landmasses. On the second landmass, the electrical power conductors of the first and second cables are electrically connected to one another, and pieces of power feed equipment located on said first and third landmasses are used to supply electrical power to devices located along lengths of the first and second cables. Alternative embodiments are also disclosed.

Abstract: If a repeater supervisory control (SV), a pre-emphasis automatic adjustment (PE), a receiving side threshold value automatic adjustment (Vth), a transmitting side dispersion compensation value setting (VDC(T)), and a receiving side dispersion compensation value setting (VDC(R)) are executed for an optical main signal, these controls are executed in the above described priority order. Accordingly, if the controls are independently executed, or if two or more controls simultaneously occur, a control with a higher priority is executed. In this way, a transmission quality of an optical signal is prevented from being badly influenced as a result that the controls are simultaneously executed.

Abstract: High power repeaters for use in amplifying optical data signals transmitted through undersea fiber optic cables are disclosed. Raman amplification schemes using 100 or more pump lasers are integrated into industry standard sized pressure vessels for amplifying optical data signals transmitted through one or more fiber optic pairs. Other repeater features include high density packaging, efficient power distribution, and component sharing.

Abstract: A system for delivering optical signals to and from an undersea optical cable may include a cable landing station connected to the undersea optical cable and configured to convey a wavelength division multiplexed optical signal from the undersea optical cable. The system may also include a point of presence that includes wavelength division multiplexing equipment configured to convert the wavelength division multiplexed optical signal to a number of optical channels. At least one terrestrial optical fiber may be coupled between the cable landing station and the point of presence to transport the wavelength division multiplexed optical signal from the cable landing station to the point of presence.

Abstract: A method and an apparatus for optical transmission line power feed interference compensation for compensating for an electrical interference signal in a power feed conductor (12; 52) and in an associated second conductor (14; 54). The interference signal may be produced by electromagnetic induction or by local variation in earth potential. The compensation is performed by producing a variable compensation signal from an electrical interference signal produced in the second conductor and inputting the variable compensation signal onto the power feed conductor, in order substantially to compensate for or cancel the electrical interference signal produced in the power feed conductor.

Abstract: A system compensates for the presence of power transients. The system receives a data signal and detects the occurrence of a power transient. The system generates a threshold signal based on the detected power transient and determines a value of the data signal based on the threshold signal.

Abstract: An optical submarine communication system has a land cable connected to a terminal apparatus which is installed on land near the seashore for transmitting an optical signal and electric power. The land cable is connected to an optical submarine cable through a beach manhole, and a repeater is connected to the optical submarine cable. The optical submarine communication system has a surge suppressor provided on the land cable, whereby a surge generated from the terminal apparatus side because of a lightning stroke or an insulation failure is suppressed and prevented from reaching and damaging the repeater.

Abstract: A bathyphotometer system is described for detecting photoluminescent signals excited by a grid disposed in a marine vehicle. The system uses photodiodes to convert the optical signals into electrical signals which are sampled, integrated and coupled to output terminals for transmission to a surface host vehicle. In one embodiment the signals are digitized and encoded as FSK tones for transmission to the surface host vehicle.

Abstract: A system of transmitting optical signals during a subsea oilfield operations comprises a subsea fiber optical signal carrier. The fiber optical signal carrier includes a first optical fiber having a least one doped section that acts as an amplifier to optical signals passing there through when the doped section is supplied with optical energy. A second optical fiber is disposed alongside the first optical fiber for carrying optical energy. An optical coupler between the second optical fiber and the at least one doped section supplies optical energy from the second optical fiber to the first optical fiber. At least one sensor provides optical signals to the first optical fiber. An optical energy source supplies optical energy to the second optical fiber.

Abstract: First to sixth optical switches 17 to 22 are provided: in event of failure on the part of a third input/output port 33, only the first and second optical switches 17 and 18 turn ON; in the event of failure on the part of a second input/output port 32, only the third and fourth optical switches 19 and 20 turn ON; and in the event of failure on the part of a first input/output port 31, only the fifth and sixth optical switches 21 and 22 turn ON.

Abstract: A branching unit, for use in optical communication systems, has three branches A, B and C each including a connection for a power feed and several inputs/outputs for optical fibers. Optical switches are provided for selectively coupling inputs/outputs of different branches to enable a routeing of optical signals through the unit. The routeing is effected in dependence upon the way in which each of the three branch connections are provided with an electrical power feed.

Abstract: To diminish the risk of interruption of traffic in a submarine optical cable system in the region of the shore where damage is most likely to occur, the landing-stage of the system has duplicated spaced-apart cables between a submerged branching unit and an onshore submarine line terminal endstation. Various changeover modes are disclosed, including those where both cables are coupled to signals at all times and changeover is accomplished by blocking amplifiers.

Abstract: A method of increasing capacity on a long-haul undersea cable system having at least one optical fiber, said method comprising interleaving counter-propagating forward-propagating and backward-propagating signals in forward and backward channels on a common optical fiber, wherein the wavelength offset between said forward and backward channels is typically half of the channel spacing of co-propagating signals.