All-optical networking Was: [Re: Notes on the Internet for Bell Heads]

Fri Jul 12 21:00:47 UTC 2002

At 12:36 PM -0700 7/12/02, Scott Granados wrote:
>Actually, research has been done that uses rare gasses to slow and even
>stop the photons down in a tube.  It would be possible to store the
>states of photons in these tubes and then release them when you wanted
>with out requiring miles of fiber.

That process requires a reference beam, and currently can only be
tuned for specific wavelengths. Decoherence also occurs fairly rapidly
in the system.

In a DWDM network, you would need as many units as there are wavelengths
in order to do a full capture.

http://www.sciencenews.org/20010127/fob1.asp

Given how fast this field is moving though, it may become practical
sooner rather than later.

>Also, photons work in pairs.
>It may be possible to split the pairs on the fiber and observe the actions in
>the fiber remotely  by capturing one side of the pair and allowing the
>others to continue.  They interact in  pairs even though physical
>distance is between them.

I think you may be thinking about quantum-entangled pairs. That
phenomena is better suited to cryptography than general networking.

In an entangled system, both recipients would know pretty quickly that they
did not receive their photons as there would be an early 'measurement' on
one end, and a missing photon on the other.

>On Fri, 12 Jul 2002, Chris Kilbourn wrote:
>
>>
>> At 2:32 PM -0400 7/12/02, Ralph Doncaster wrote:
>> >> Add in the fact that optical sniffing, while not impossible by any means
>> >> today, will increasingly become non-trivial as bandwidth increases. Which
>> >> is exactly one of the 'problems' they expect optical network to solve.
>> >
>> >You mean just expensive, right? i.e. a couple transponders and an OC48 or
>> >OC192 switch.
>>
>> Cost is a factor, certainly, but the storage of the captured
>> data becomes the larger problem.
>>
>> In the TB or PB range of optical data transmission, where and how do you
>> store the captured information? Unless you have TB's of solid state drives
>> to stream electrons into after an optoelectronic photon -> electron
>> conversion your only other option is to store the photons in loops of
>> fiber with an optical repeater.
>>
>> Until we have quantum computers which might be able to parse the data in
>> real-time, we still need a buffer to store the data in before we can
>> look for the needle in the haystack.
>>
>> Even with some nifty filtering on the sniffer, you're potentially
>> looking at obscenely large amounts of information to store.
>>
>> I would expect that the distance of fiber you will need to store the
>> data in will be the gating factor, which means it tilts more towards a
>> physical issue than a cost issue.
>>
>> If I need a few thousand kilometers of fiber as a storage loop, it's
>> kind of hard to move around efficiently. :-)

Regards,

Chris Kilbourn
Founder
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