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MSNBC on Infinera's Optical Chip
pnoti writes: "This article at MSNBC is a loose overview of Infinera's new chip with circuits that control the flow of light instead of the flow of electrons. 'If this chip performed as they hoped, it would shatter many of the theoretical limits regarding the behavior of light in optical communications networks.'" Update: 04/10 04:26 GMT by T : That's MSNBC, not The New York Times -- oops.
Yeah, Red Herring carried the story, and with a little lower "fluff factor". At least, it seemed to me . . .
The Gardener
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Slashdot is not the only publication with bad editors! To quote the article: "Though Infinera won't reveal the chip's cost, when built with manufacturing techniques used by chip makers like Intel and Advanced Micro Devices, it likely could be made very cheaply."
Well, not quite. You see, the article later mentions that Infinera used InP (Indium Phosphide) chips instead of silicon, probably because they needed it's superior electrical and optical properties. With InP, it's possible to make 100 GHz circuits, but not cheaply. Certainly not for the same cost as a modern, silicon CPU.
At least there is one current example of this today. There are devices that are used to tap optical fibre lines, that work by actually splicing into the line.
These devices have been around for a number of years now, and I have heard of one such device being able to tap an optical fibre bundle that has 50 individual optical fibres within it. Of course it will leave the optical pathways semi-intact, and detection is only by using complex test gear on either end that will tell you the consistency of the fibre as well as the points where the joins have been made. These things are usefull if you want to wiretap an optical fibre cable.
Of course removing such a device from the optical fibre bundle will effectively break the connection.
I'm not so sure that photons not having mass means that they have no inertia. Photons have momentum, can exert a (very) slight pressure, and can be pulled on by gravity. Given that, their inertia is likely to me small, but nonzero.
...This one keeps the flow going pretty steadily. :-D
CAn'T CompreHend SARcaSm?
Being pulled-on by gravity doesn't mean anything. Gravity (according to Einstein) is the warping of space-time, so things that are massless still experience it. According to Newton's equations, that wasn't the case.
Ah, glad to see a fellow P Chem student here! I have my book handy, and so I figured I'd make a stab at posting that more precise explanation you asked for.
Tunneling has to do with the energy of the particle. In the one-dimensional particle in the box theory, the transmission coefficient T is given by an equation that I cannot reproduce due to the ascii art issues, but is a roughly second-order polynomial curve when plotted as T versus E/V0, where E is the energy of the particle and V0 is the "height" of the potential barrier, moving from T=0 at E/V0=0 to T=~1 at E/V0=~2. This would mean that the higher energy of the particle, the higher of a potential barrier needed to prevent tunneling. Now, free electrons have higher energy than photons, so it would be harder to contain them, as it were. Plus, this isn't the only issue. Photons have no charge, and so are undisturbed by electrical and magnetic fields, but electrons of course are negatively charged, which complicates things in 2 main ways, first they do not travel in a straight line (like photons), and having 2 narrowly separated regions with different charges (such as in a transistor) will lower the potential barrier. I believe this is why SOI (silicon-on-insulator) is useful, as it makes it more difficult for the electrons to migrate from region to region.
I hope this helps some, and if I am wrong, feel free to correct me!