An object to provide a submarine optical transmission apparatus capable of efficiently housing optical components and electric components. First component housing units can house either or both of an optical component and an electric component and are stacked in a Z-direction. A case can house the first component housing units and a longitudinal direction thereof is an X-direction. A heat dissipating member is disposed in the case and conducts heat generated in the first component housing units to the case.

A common component assembly is provided for a cable joint for joining a first submarine optical cable and a second submarine optical cable. The assembly includes a first end face including a first opening and a first flange for connection to a first cable termination unit of an undersea optical cable joint. The assembly also includes a second end face including a second opening and a second flange for connection to a second cable termination unit of an undersea optical cable joint. The assembly further includes a fiber tray connecting the first end face to the second end face. In addition, the assembly includes an optical assembly connected to a first side of the fiber tray. The optical assembly includes a free space optical add/drop multiplexer.

Embodiments of the present invention provide a unique new approach to generating operating condition information used for assessing flow assurance and structural integrity. More specifically, apparatuses, systems and methods configured in accordance with embodiments of the present invention enable multiplexed arrangement of optical fiber for sensing of operating conditions within a structural member and utilize fiber optic sensors for enabling monitoring of operating condition information within one or more elongated tubular members. To this end, fiber optic sensors are strategically placed at a plurality of locations along a length of each elongated tubular member thereby allowing critical operating conditions such as strain, temperature and pressure of the elongated tubular member and/or a fluid therein to be monitored. A multiplexing unit is used for allowing selective configuration of individual lengths of optical fiber for creating one or more contiguous optical fiber structures.

Embodiments of the present invention provide a unique new approach to generating operating condition information used for assessing flow assurance and structural integrity. More specifically, apparatuses, systems and methods configured in accordance with embodiments of the present invention enable multiplexed arrangement of optical fiber for sensing of operating conditions within a structural member and utilize fiber optic sensors for enabling monitoring of operating condition information within one or more elongated tubular members. To this end, fiber optic sensors are strategically placed at a plurality of locations along a length of each elongated tubular member thereby allowing critical operating conditions such as strain, temperature and pressure of the elongated tubular member and/or a fluid therein to be monitored. A multiplexing unit is used for allowing selective configuration of individual lengths of optical fiber for creating one or more contiguous optical fiber structures.

The systems and methods described herein provide a submarine optical repeater in which a plurality of thermally conductive, electrically insulative, ceramic members form a hollow structure having an interior volume that is maintained at a relatively high first voltage when compared to a relatively low second voltage maintained external to the hollow structure. A conductive element at the first voltage disposed in the interior volume provides power to optical repeaters disposed on the interior surface of the hollow structure. Power flows radially outward from the conductive element to the optical repeaters to the surrounding environment about the submarine optical repeater. The thermally conductive ceramic members electrically isolate the optical repeaters from the second voltage while providing a thermally conductive pathway for the heat generated during the operation of the optical repeaters to dissipate into the surrounding environment.

This application relates to methods and apparatus for monitoring power cables (100) carrying multiple AC phases to detect deformation of the power cable. A distributed fibre optic interrogator unit (302) is used to interrogate a sensing optical fibre (301) coupled to the power cable to provide a measurement signal from each of a plurality of longitudinal sensing portions of the sensing optical fibre. An analyser (602) is configured to analyse the measurements signals to detect a characteristic of an imbalance in magnetic fields. The characteristic may be a signal component with a characteristic frequency related to the power frequency and number of AC phases, the sensing optical fibre may be sensitised to magnetic fields and the characteristic frequency may be 2n times the power frequency where n is the number of phases, e.g. six times the power frequency for three phase AC.

Systems and methods of undersea optical communication are provided. An undersea optical amplifier assembly can include a water-tight housing and a photonic integrated circuit disposed within the housing. The photonic integrated circuit includes a plurality of optical fiber inputs, each configured to receive an end of a respective optical fiber of a first fiber optic cable bundle, and a plurality of optical fiber outputs. Each optical fiber output corresponds to a respective optical fiber input to form a fiber optic input-output pair, and is configured to receive an end of a respective optical fiber of a second fiber optic cable bundle. The photonic integrated circuit includes an optical amplifier optically coupled to each respective fiber optic input-output pair. The housing includes a first water-tight access port configured to receive the first fiber optic cable bundle, and a second water-tight access port configured to receive a second fiber optic cable bundle.

Pipeline segments can contain cables, such as communication cables (e.g., fiber optic cables) within insulation material surrounding the pipeline segments. Cables can be embedded within the insulation material, run through conduits embedded within the insulation material, placed in channels formed in the insulation material, or otherwise. Channels containing one or more cables can be filled with supplemental insulation material, thus securing the cables within the channels. Pipelines created as disclosed herein can enable data transfer between distant points without the need to lay fiber optic cable in addition to the pipeline. Further, fiber optic cable embedded thusly can be used to sense conditions in the pipeline, such as leaks, seismic activity, strain, and temperature information.

An undersea fiber optic cable architecture including a beach manhole (BMH) installed at a terrestrial site, a terrestrial station connected to the BMH by a terrestrial fiber optic cable, a first landing cable extending from the BMH into territorial waters adjacent the terrestrial site and connected to a first enhanced branching unit (EBU) located in the territorial waters, a second landing cable extending from the BMH into the territorial waters and connected to a second EBU located in the territorial waters, a recovery path cable connecting the first EBU to the second EBU, a first trunk cable extending from the first EBU into international waters, and a second trunk cable extending from the second EBU into the international waters.

Aspects of the present disclosure describe systems, methods. and structures directed to an integrated 3-way branching unit switch module suitable for undersea application.