"Father of Fiber Optics" Wins Nobel Prize 74
alphadogg writes "Charles Kao, whose work in the 1960s laid the foundation for today's long-distance fiber-optic networks, has won a share of this year's Nobel Prize in Physics (PDF). Kao, sometimes referred to as the 'father of fiber-optic communications,' was formally honored by the Nobel Foundation in Stockholm, Sweden 'for groundbreaking achievements concerning the transmission of light in fibers for optical communication.' Kao's breakthrough discovery in 1966 was to determine how to transmit light over long distances using ultrapure optical glass fibers. This would extend the distance of such transmissions to 62 miles vs. the mere 65 feet allowed under previous technology held back by impurities. The first ultrapure fiber was created in 1970."
No love for the inventors of the CCD? (Score:5, Informative)
These guys [about.com] also got the Nobel prize this year for their work on the CCD. That's worth a mention too, I think!
Re:62 miles in the 70's (Score:5, Informative)
This is at 2.5 Gbps.
I don't know if that's a lot or not, but that's around where we max out.
Fiber optics took about 20 years to arrive (Score:4, Informative)
I did my MSEE thesis in 1981, working on mono-mode optical fibers. This was still pretty cutting edge at the time, but the first semi-automatic splicing units had started to arrive.
The most fascinating feature of very pure optical fibers is that they have two minima not too far apart:
At around 1200 nm the frequency dispersion is very close to zero, which means that a single pulse traveling along the fiber will suffer minimum smearing, which maximizes the possible bandwidth.
At around 1500 nm the optical damping (i.e. sum of scattering & absorption) has a minimum, which means that by using this frequency you can maximize the distance between repeaters.
Anyway, it took about 20 years (i.e. around 2001) before mono-mode fibers become standard in all new installations here in Norway, it seems like this is the normal time to go from lab prototypes to SOP.
Terje
Re:No love for the inventors of the CCD? (Score:2, Informative)
Re:Shares of the Nobel Prize (Score:4, Informative)
Re:Why 62 miles? (Score:3, Informative)
The other problem is that total internal reflection relies on the photons hitting the inside of the glass at quite a sharp angle. Impurities in the manufacturing can result in places where photons fail to reflect and just leak out (you can see this by shining a light in one end of a drum of fibre optic cables in the dark and watching the entire length glow slightly). If you are sending individual photons this is a big problem, but you're probably sending little bursts of them. When you do that, some proportion will be lost over each unit length of the fibre and after a certain distance insufficient will be left to be detectable at the far end.