SubCom’s custom-built repeaters have evolved from the groundbreaking
technology developed in the 1950s at the renowned Bell Laboratories.
At their core, the advanced repeaters each contain an Amplifier Pair — an assembly of
sub-components all made by SubCom, consisting of:
- Optical Pump Unit — an electro-optical active module that pumps Erbium and acts
as the circuitry for the laser signals
- High Loss Loop Back Assembly — a passive, bidirectional line-monitoring module
that helps determine the health of the system
- Erbium Doped Fiber Assembly — a module that contains the Erbium amplification
media and also filters out noise and interference to deliver the clearest possible
After passing rigorous certification testing, amplifier pairs, or amp pairs, are
transported into Network Assembly Operations. Within a Class 100 clean room,
engineers merge from one to eight amp pair units into an integrated repeater
network. The assembled network is next inserted into its cylinder housing, which is
capped and coned at either end, enabling connections with the cable at specified
Though extremely compact, SubCom’s repeaters house a tremendous
amount of complex network technology, which makes their ability to withstand harsh
environmental stress screenings even more impressive. Absorbing heavy shock and
vibration tests, the repeaters experience the harsh conditions replicating those found
in oceanic settings.
Moving next into the Enclosure Integration phase, repeaters are covered with seals
before they proceed through an automated cover-splicing operation designed to
protect the multiple fibers at all points along the line. Once again, they are tested for
reliability and endurance.
The SubCom repeaters have an extremely high level of reliability,
with over 2,300 repeaters deployed (11,900 amp pairs). The repeaters are produced
with 18 and 28 nm optical bandwidths, output power to 15.5 dBm, and up to eight
amplifier pairs. The passive optical loop-back networks support effective fault location
in repeaters and cable spans.
Finished, assembled, and extensively tested, repeaters are now ready to be integrated
Operating in parallel with repeater manufacturing, SubCom’s cable
production begins with the Unit Fiber Structure Process. In this initial phase, the
delicate, individual electro-optic fibers are encapsulated within a plastic tube to
provide protection and support during the manufacturing process.
SubCom’s quality control specialists apply testing at every step to
monitor all cable features and functions, including tension, temperature, diameter
gauge, and optical performance.
Step two in cable manufacturing is the Power Conductor Process during which steel
wires are wrapped around the Unit Fiber Structures to increase the cable’s strength.
Copper tape — formed into a tube — is welded onto and around the package,
providing a power circuit, as well as a hermetic barrier to keep out hydrogen.
Moving to the Extrusion Process, an extruded polyethylene jacket is wrapped over
the copper to serve as an insulator. The end product at this stage is light-weight cable,
scalable to the customer’s need and application.
If needed, the cable is encased in an armor coating of galvanized steel wires, nylon
serving, and tar coating. The Armoring Process protects the cable in rugged undersea
The submarine cables that are produced contain and protect optical fibers and
electrical conductors and can withstand harsh environmental conditions for 25 years.
While these cables are extremely durable, they are flexible enough to support system
deployment, recovery, repair, and re-deployment. The cables are tested to withstand
a variety of stresses, including temperature, tension, torsion, pressure, chemical
exposure, and bending, all while being non-threatening to the undersea environment.
Finishing the assembly stage, the completed cables — divided into customized lengths — are coupled with optical amplifiers, splice boxes and branching units and
then wound as a continuous span onto the ships’ tanks.
SubCom provides a broad choice of breaking strength, working
load and fiber counts. To accommodate every sea bed or underground condition, they
are available in multiple configurations: lightweight, special applications, light weight
armor, single armor, double armor high strength, double armor high abrasion, and
Cable Diagram and specs (PDF)
Quality Certificate link (PDF)
The joints produced at the wet plant facility provide optical, electrical, and mechanical
continuity between cable sections. The joints are used for several applications,
including cable-to-cable, cable-to-repeater, cable end seal, and cable-to-branching
SubCom recognizes that our customers have made considerable
investments in their telecommunications systems. That’s why we invest significant
resources in all our manufacturing processes and facilities. As a result,
SubCom minimizes repair needs after a cable system has been installed.
Plus, we apply exacting calculations to reduce mean time to failure and deliver a
maximum degree of system reliability.