What's amazing to me is that these cables were laid without a lot of fanfare. Seems to me if I were Level1 or whoever else and had just completed a 10,000 km cable across an ocean, I'd make sure the press release saw some circulation.
The same thing with satellite launches. I feel like these are fairly major feats of engineering that go basically unheard of unless you're in certain small circles.
Modern telecoms cable is some amazing stuff. These days there's no metal in the entire cable. Instead, it's all lasers through glass fiber, and when the signal attenuates, it gets boosted by passing through sections of doped fiber that lase using power from another beam, adding power to the signal. And we can do this just as easily as the people back then dropped telegraph cable. For me, at least, there's always something to be impressed by.
First, most EDFA (Erbium Doped Fiber Amplifiers) need power to operate since the lasers that perform the pumping action are local to the doped sections of fiber.
Second, most submarine cables make extensive use of Raman amplification which leverages the transmission fiber as a gain medium via forward or backward pumping of lasers with frequencies chosen to produce Raman gain.
In both cases, you need an amplifier every 70-100km (150km in some cases) in order to have a usable signal on a long span.
Raman amps are pretty cool but tricky. For one thing, the power required is pretty high. +1W dBm isn't uncommon for certain Raman amps. At those power levels, you need to be careful you dont cause burns to personel when they are working on the equipment.
The power to run the lasers is usually carried on conductors that are part of the cable itself. The voltages are somewhere in the several kilovolt range so laying submarine cable is also kinda like laying a high-volage transmission line across the ocean.
It's so weird because I think it's such an impressive feat and one of those things that I feel should be technically really challenging yet it was done so long ago. Sometimes I learn things and am shocked because I either thought accomplishing the thing would be easy and it turns out to be insanely hard or vice versa. This is the latter.
> I'd make sure the press release saw some circulation.
A bunch of it was laid by ATT, which then got bought by Tyco.
The entry of that NJ HQ building was wild: It had pics of the ships used to maintain the cables. (When the cable needs to be pulled up in the middle of the atlantic, it's a bit of a challenge.)
IIRC, Tyco had 9 ships. If you glanced quickly, they looked like battleships with all the equipment on them. It was quite the operation.
The same thing with satellite launches. I feel like these are fairly major feats of engineering that go basically unheard of unless you're in certain small circles.