Universal Jointing for Submarine Cables
ujconsortium.com
ujconsortium.com
"This fusion splicer automatically aligns a pair of optical fibers in both the X and Y (horizontal and vertical) planes and then fuses them together with heat from an electric arc to form a low-loss splice. Improved image processing software of this fusion splicer enables precise core alignment and accurately estimated splice loss. A tensile proof test that is carried out by applying tension to the fusion splice verifies the long-term reliability of the fiber splice. Following a successful proof test, a heat-shrinkable splice protection sleeve is installed over the bare glass fiber and cured in the built-in heater."
Here's a video of a similar fusion splicer for land-based use.[2] The fussy part of aligning the fibers is automated now.
The "universal jointing" thing seems to be more about joining all the outer layers of an undersea cable that give it protection and tensile strength. After the fiber has been spliced, all that outer protection has to be joined, too. Visualize a heavy hose wrapped around a steel strand bridge cable wrapped around a coax cable with a fiber optic strand at the center. Now connect two of those sturdily enough to spend 25 years on the ocean bottom.
[1] https://ujconsortium.com/information/fusion-splicer-ujs-s200
Their energy source is not electrical, but also optical, i.e. light produced by a laser with a different frequency from the frequencies used for data transmission and which is also sent through optical fibers.
In current speech, laser is used mostly to mean optical oscillators, which generate light, but actually the laser is only the optical amplifier and it must be inserted in an optical resonator in order to make a generator of light. In the amplifiers for optical fibers, only the laser part is inserted in the fibers, without an optical resonator (i.e. without mirrors), so it does not generate light, but it amplifies the light passing through it.
The erbium-doped lasers function exactly like any other solid-state lasers, which typically use crystals of sapphire or of YAG or glasses doped with ions of chromium (ruby lasers) or of neodymium or of titanium, but erbium is chosen instead of the more common dopants because it amplifies light in the frequency band used for optical fibers.
So the cables with optical fibers do not need any electrical connection for providing amplification in intermediate points when the distance between the ends of the cable is too great.
How does the fusion splice process take place deep under water?
Animated video from a company that does this: [1]
The US did this in the Cold War as Operation Ivy Bells. A spy leaked this to the soviets who then retrieved a tap.
But it went on. Nowadays the US operates the USS Jimmy Carter and the Russians have a whole directorate, GUGI, operating a fleet of special submarines and surface ships.
Links: http://www.hisutton.com/Secret%20Sub%20-%20USS%20Halibut.htm...
Which obviously makes more sense, but I was really curious to learn about this new problem I’d never considered about construction of submarines :)
In many languages such ambiguities are impossible, because the nouns, verbs and adjectives derived from the same stem use distinct affixes to mark the role of the word.