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Intel Announces Lasers On a Chip
wonkavader writes, "The New York Times reports that 'Researchers plan to announce on Monday that they have created a silicon-based chip that can produce laser beams. The advance will make it possible to use laser light rather than wires to send data between chips, removing the most significant bottleneck in computer design.' The work is from Intel and the University of California, Santa Barbara. This suggests breakthroughs in both computing performance and networking." From the article: "The breakthrough was achieved by bonding a layer of light-emitting indium phosphide onto the surface of a standard silicon chip etched with special channels that act as light-wave guides. The resulting sandwich has the potential to create on a computer chip hundreds and possibly thousands of tiny, bright lasers that can be switched on and off billions of times a second." Further details in the Intel press release.
. . . to be announced shortly.
One CPU cycle wasted on digital restrictions management is ONE TOO MANY.
And Tron is yet another step closer to fact.
Log Buffer
They've been trying to build optical computing chips since the 1980s. I did a summer internship in Japan in 1990, when they were making custom batches of exotic rare-earth crystals for fiber-optic relay stations.
For blue LEDs used by case modders. Why bother when the chips are flashing all by themselves.
It may look like I'm doing nothing, but I'm actively waiting for my problems to go away.
--Scott Adams
I think this will be of more use to optical switching - if you have the ability to switch and route on your fibernetwork without changing from optical to electrical and back again you can switch much faster and more efficiently.
Great company. Real solid and with great integrity. I'm sure they'll put lasers to great use. Yes, x86 is horrible, but that too will pass.
Obviously this boosts bandwidth and cuts latency (like mad), but doesn't this kill the current FSB speed and multiplier method? I mean, your clock speed is FSB clock x multiplier, so what happens if you replace the FSB with a laser?
From what I recall in physics class electrons travel at 2/3 c. So at best this means that memories and chips can be 50% further apart, or that clocks can go 50% faster. Or is there more to this?
The future of IM:
- Hey look at what I'm sending you!
- ARGH! MY EYES!!!
Seriously, are these lasers safe?
This makes me wonder about the future new techniques this could be used for. Never mind the obvious inter-chip communication...how about visual systems?
Could this, with another 10 years of evolution and the advancement of color coordination and multi-colored laser chips, provide incredibly high contrast and accurate projections? This is like DLP projectors on steroids. They don't simply reflect light one pixel at at time, they actually create the laser one pixel at a time.
I also was wondering what the 3D applications would be like. Perhaps an R2D2 unit fitted with one of these would have a much sharper and sexier image of the princess asking for OB1's help.
Also, how about a laser weapon targeting system that can lase 100 targets at once for all the bomblets?
Great things are going on in my mind.
Who is this that even the wind and the waves obey Him? Surely this computer must submit also!
I don't want any lasers on my annals, that's for sure!
The AACS key is NOT 0xF606EEFD628B1CA427BEA93A9CA9773F
Put a lot of people who know a bit about computer science (linux, PHP, etc. ) and have them comment on a hard science. They don't even know enough hard physics and math to even rate their own skills. All they can do is joke about it. Enough with the sharks.
I was at a conference last weel (http://www.ieee.org/organizations/society/leos/LE OSCONF/GFP2006/index.html) were this was presented by John Bowers. As they explain briefly in the article, they are bonding InP to Silicon wafers. The silicon provides the waveguiding, and enough of the mode is in the InP to give them gain. They achieved an optically pumped laser, and were still working on an electrically pumped one. I wonder if this announcement will mean that they achieved electrically pumped lasing.
It's good work, but I'm not sure if the bonding process will ever be suitable for monolithography integrated CMOS and photonics. I was more impressed by the work done in Huffaker's lab (http://www.chtm.unm.edu/huffaker/index.html) where they are working on growing III-V materials directly on silicon. However, the work by Bowers is more mature and will lead to devices sooner.
I be it will take at least 5 to 10 years to see this on a standard desktop/server system.
My biggest concern is reliability. How many people are running SANS with redundant Fiber optic connections. Why? because the lasers fail. Could you imagine if you had a motherboard built with multiple lasers for on board communication. Yeah it would be fast, right up until the time one of those lasers failed.
InP lasers on silicon is new technology and is quite a ways from being producible in a mass market chip. Manufacturers have enough trouble getting gates, isolation, contacts for silicon devices reproduced. Now tell them to create a step where they put a laser in there and I bet it will take them 2-3 years design and 3 years to get a manufacturing process. (Can anyone say copper level metal?).
Hopefully this isn't something that completely patentable, because this is where the consumers would benefit from competition.
From a manufacturing perspective, I would rather be stuck trying to implement TaO gates.
He who said 1,000,000 monkeys on 1,000,000 typewriters would eventually type the great novel, never saw an AOL chat room
By using optical links, this breakthough will solve some of the problems we have today with sending data at high speed across chip to chip busses. The major problem today with sending data at high rates between chips is the losses incurred by travelling across the FR-4 PCB. As the data rates go up, the greater the losses incurred, the more difficult it is to recover the data being sent. Optical interconnects have significantly less losses at high data rates, thus making them a suitable technology for chip to chip communications in the future. This is a breakthrough because now we can integrate exotic optical materials with low cost silicon using standard chip-making equipment. This was something that could not be done in the past.
I just had a course on advanced VLSI design, where the Professor relies on [Kibar, VanBlerkom, Fan, Esener, J Lightwave Techn., vol. 17, p. 546, 1999] to approximate a couple of Watts for optical interconnects. This is clearly not acceptable.
I'm interrested in how they manage to keep the power consumption reasonable. Till then, I call hype!
Res publica non dominetur
No. Not like that. That uses compound semiconductors like GaAs (gallium arsenide).
Intel is now making lasers with silicon substrate.
However, if your point is that is isn't quite new, OK. Intel announced this originally back in February 2005 [http://en.wikipedia.org/wiki/Raman_laser]
...the future crusty old bastards are already drinking the Kool-Aid.
Electronic signals travel pretty damn close to c. The problem is that electrons are fermions and as a result are antisocial by the Pauli exclusion principle no more than 2 in each location. Charge makes this even worse. On the other hand photons are boson and they like to hang out in the same location. As a result electrons are handy when you want bits to interact (logic gates, memory) while photons are handy when you want bits to pass through each other (communications etc.). The advantage of using photons is that you can make connections without EMI or other cross talk problems. In addition there is some very nifty quantum computing you can do with such systems (the topic of my dissertation).
One huge advantage could be an orders-of-magnitude reduction in the current necessary to drive signals off-chip. (It's not mentioned in the article whether these drivers have a power advantage) Off-chip drivers are a significant source of current drain in a chip, and if this technique eliminates the necessity to wiggle the off-chip capacitive loads at high frequencies, then you'll see much lower power. And if each pin on the output bus is drawing less power, you may see larger bus sizes and more bandwidth between chips.
Who do you get to be an expert to tell you something's not obvious? The least insightful person you can find? -J Roberts
1. Why lasers? Why not just light? At the distances they're talking, does coherence and phase matter? Incoherent light is just as fast, and if you're shooting it into waveguides and it's coming out the other end, as long as you're not multiplexing data on a given waveguide what advantage does this give? (I honestly don't know: maybe there's a great reason.)
2. They're still bonding indium phosphide onto an existing chip. When they can use photolithography to build a billion lasers on the chip itself, rather than having to glue separate lasers onto a chip, that'll be really impressive. That's why so much effort is being focussed (pardon me) on developing silicon lasers rather than exotics attached to silicon.
Nostalgia's not what it used to be.
Actually, you are both right and wrong.
The old anouncement uses Raman gain- where you throw shitloads of optical power down a waveguide (or fiber) at one wavelength and you get new light at another. For this to happen, you only need a silicon waveguide (and perhaps some electronics to pull out carriers that are formed).
In this new case they are bonding InP (a III-V material like GaAs) to silicon. This hybrid device allows the light to be guided mostly by the silicon, but the gain is occuring in the InP in a typical way.
You are correct, the average velocity of a given electron in a DC circuit is pitifully slow. I think it takes an hour for an electron to make it from the battery through the starter switch and into the solenoid. This is because the electron starts to take off, runs into an atom and bounces backwards like a bouncy ball, hits something else and bounces forward, etc. Hence why we discuss the average velocity. You might also want to look up drift velocity.
However, the electromotive force (emf, colloquially referred to as voltage) propagates as an electromagnetic wave. The speed that it propagates at is dependent on the permittivity of the material it is propagating through.
IIRC from my VLSI class, if you take into account the permittivity of silicon, electrical signals (emf; voltage) propagate at approximately 2/3rds of the speed of light.
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