Internet Across the Ocean


Optical submarine repeaters are big missile shaped devices that lie along undersea cables carrying almost all of the world’s Internet traffic and are supposed to carry internet across the ocean. They have a 25 year lifespan powered by the copper cables which are wrapped around the fiber optic cable up to 15kV DC with a power supply on either end of the cable.

As it is laid on the sea bed, the optical submarine repeater should be maintenance-free. Therefore, it is designed to achieve high potential and reliability by applying the following technologies.
1) Direct optical amplification: This repeater employs optical amplifiers using erbium-doped fibers (EDF) and 980 nm pump laser diodes (LDs). The pump LDs support a redundant configuration in order to realize high reliability.
2) High reliability: The optical submarine repeater gains high reliability by applying advanced LSI technology and high-reliability components.
3) High resistance to water pressure and high performance sealing: The housing of the submarine repeater is designed to withstand any pressure of 8,000 m water depth. The high performance sealing technology is based on versatile years of experience in the field of submarine repeaters for coaxial systems.
4) All-optical monitoring: In order to implement a high reliability monitoring system, an all-optical monitoring system is applied because this does not require electrical circuitry inside the submarine repeater.

Submarine Cable Map
Submarine Cable Map

This video provides a brief description, let’s go inside the NEC plant that makes them.