I want to know what optics they are using. On segments that are 7,000 miles long - are there active optic splice boxes along the length of the cable? Or are they using lasers that actually push 7K miles?
If you want to see what they look like: http://www.nec.com/en/global/prod/nw/submarine/product/ns-se...
Look at the last page for a photo of one of the amps with people in the frame for scale.
Is that a single strand they are amplifying with these? I'd like to find cost figures for how much it is to run a single fiber trans-oceanically (if thats a word).
I am still interested in who's optics/equipment are in those repeater stacks and how they power them.
http://en.m.wikipedia.org/wiki/Optical_amplifier#Doped_fiber...
But seriously, that is damn cool - while I have been in IT/networking for a long time - I was not aware of "pumping lasers" as everything I have done, even in designing massive fiber cable plants have all been for relatively short distances.
I wouldn't be surprised if both methods have been used in different situations or at different times.
Are you saying that there's an extra "pumping fiber" in the bundle, fed by a pumping laser on shore? Or are the pumping lasers in the repeaters, in which case there would still need to be electrical power supplied down the cable to drive the pumping lasers?
It's my understanding that the pumping laser would be a different wavelength carried by the same fiber (just as a fiber can carry multiple data channels using different wavelengths in DWDM). The boost happens because of the special doped section.
Laser pumping is used extensively in laser physics, at places like the NIF: https://lasers.llnl.gov/about/nif/how_nif_works/injection_la...
The pumping laser essentially puts the doped medium in an energy condition where the data transmission can stimulate additional emission (similar to how lasers work in the first place). Few photons in, many out. The energy required to do so comes from the pumping laser.