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How do optical cables carry data across the world?

Hi,

So I read that optical cables can only carry light for around 60 miles. It begs the question, how on earth do undersea fibre optic cables work? e.g. the one under the atlantic? How does that carry data if the limit is 60 miles?


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(edited 1 year ago)
Reply 1
Yeah. Light can only go so far, however, undersea fiber optics design constitutes cladding of the cable with glass together with the use of light pulses allows light to go further compared to other optic cables by bouncing of the light on the glass. The glass is designed with edges and angles to ensure the light is oriented in the right direction. The design of the fiber optics is what allows it to transmit over long distances.

https://www.nytimes.com/interactive/2019/03/10/technology/internet-cables-oceans.htmlHi,

So I read that optical cables can only carry light for around 60 miles. It begs the question, how on earth do undersea fibre optic cables work? e.g. the one under the atlantic? How does that carry data if the limit is 60 miles?


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Original post by boulderingislife
Hi,

So I read that optical cables can only carry light for around 60 miles. It begs the question, how on earth do undersea fibre optic cables work? e.g. the one under the atlantic? How does that carry data if the limit is 60 miles?


My understanding is that the fibre has signal repeaters at intervals.
Original post by martin7
My understanding is that the fibre has signal repeaters at intervals.


I can see that working on land, but how on earth do you get a signal repeater into an undersea cable? only thing I can think of is some kind of built in repeater (light bulb at 60 mile intervals to boost the signal or whatever, and then some kind of separate strange of cable to provide the electricity for this to work! That's my guess. Hopefully someone with more knowledge on this posts something! I'm mega intrigued!
Original post by boulderingislife
I can see that working on land, but how on earth do you get a signal repeater into an undersea cable? only thing I can think of is some kind of built in repeater (light bulb at 60 mile intervals to boost the signal or whatever, and then some kind of separate strange of cable to provide the electricity for this to work! That's my guess. Hopefully someone with more knowledge on this posts something! I'm mega intrigued!

There's some information on Wikipedia: https://en.wikipedia.org/wiki/Submarine_communications_cable#Optical_telecommunications_cables

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