Intel Announces Laser Breakthrough

AdmiralWeirdbeard writes "Intel has just announced a breakthrough in laser technology allowing a continuous laser wave on a silicon chip. Apparently they devised a method to sap the interfering field of electrons previously generated in silicon by the lasers. Intel says that hardware exploiting the advance might begin appearing at the end of the decade."

Comments

Correct Units?

[FalconZero]

The (first) article states the waveguide is 1.5x1.55micrometers and 48millimeters in length, Has it got the units right on that one?
That 48mm seems awfully big (~38,000 times bigger than the other dimensions). IANAEE, so maybe its correct, but their going to refine it, or maybe its not linear.
If it is 48mm though, thats one hell of a long die, unless Intel are going to start making REALLY BIG chips.

Re:Correct Units?

[pclminion]

That 48mm seems awfully big

It has to be, for efficiency purposes.

The reason laser light is coherent is because it travels an enormous distance before being emitted. This gives the individuals waves time to become coherent. Normally, this "enormous distance" is implemented by having the light bounce back and forth between two mirrors a large number of times. However, every time the light hits a mirror you lose a bit of energy. So, if the cavity is short, you must have a higher gain in order to get the required energy, because the laser has to make more reflections in order to travel the required distance to become coherent.

Re:Correct Units?

[Anonymous Coward]

The CHIP is 16mmx16mm, the waveguide built into the chip is "folded" to fit 1.5x1.55x48000 micrometers.

Bet it you look at a road map of any city, you will find that the sum of the length of all the lines on the page is greater then the any of lengths of the edges of the map, too.

But I have a more fundamental question, one which I have not been able to determine in spite of having read the cited articles (Yes, we A.C.s CAN read the fine articles on occasion):

WHAT IS THE WAVELENGTH OF THE OUTPUT???????????

IANASLS (I am not a silicon laser scientist), but if I was would I be able to calculate the wavelength from all the values tossed about in the articles? Continuous red lasers are no big deal, a continuous violet laser would be reasonably impressive (at least to me, but I like purple), a continous deep UV or better laser on a chip this size would make for lousy light shows at the planetarium but could bring the cost down on communications central offices by several orders of magnitude, even more so if the output can be tuned. Or something like that.

It took reading the Intel glossary to the Intel press release to find the following:

Wavelength conversion - The process of taking light of one wavelength (color) and changing it to another wavelength (color). In communications, more data can be transmitted by sending multiple wavelengths of light down the same optical fiber. Wavelength conversion allows the switching of data from one wavelength to another. The Raman effect in silicon can produce such a wavelength conversion.

Which still doesn't tell me the wavelength of the laser (or the range of wavelengths), but only that the effect Intel is exploiting COULD probably produce multiple wavelengths across some undefined range.

P.S. To all the news sites that took Intel's press release and just moved sentences around to make it look like some thought or maybe even research went into the writing instead of merely repeating the Intel press release, most universities (at least my alma mater) consider that a crime more heinous then 2nd degree murder. If you wanted to be a writer, WRITE!

Re:Correct Units?

[Hal-9001]

I rebut that link in this reply to one of your other comments. The feedback due to the mirrors does contribute to the spatial coherence of the beam, but ultimately it depends on the fact that the stimulated emission process is temporally-coherent (in-phase). A Q-switched laser is a simple counterexample (at least to an optical physicist). Another simple counterexample that I neglected to mention in that other post is this. According to your theory, if I remove the laser medium from the laser and shine light into the former laser from one end, the output from the other end should be spatially-coherent light. This non-laser laser is actually a device called a Fabry-Perot interferometer, and it does not cause spatially-incoherent light to become spatially-coherent (also a simple experiment to do in an optics lab). Thus feedback is insufficient to explain the spatial coherence of a laser.

For a proper treatment of coherence, I recommend Statistical Optics by Joseph Goodman, or if you're a masochist you can attempt to tackle Optical Coherence and Quantum Optics by Leonard Mandel and Emil Wolf. :-p

Here's to hoping

[Admiral Ackbar 8]

That this will lead to optical computing, but after reading the BBC article its clear that they have it in mind to use this for optical switches in the telecomunications industry. If someone smart could come up with a silicon based optical NAND gate, we would all be happy campers.

Catch 22

[karvind]

From the nature article: Rong's chip produces laser light when it is 'pumped' with another laser.

This is old stuff (see bottom note on the article, result was published in Oct 2004). Intel showed they can lase silicon with another laser. So how am I going to find another laser to pump this one ?

Silicon is indirect bandgap semiconductor. There is no easy way to make lasers out of it unless you introduce some traps to facilitate optical transistions. Can anyone explain how does it work ? -a

Power supply...

[jim_v2000]

The article didn't mention this, or I didn't see it, but wouldn't using lasers instead of wires really use a lot of power? Epecially when you start using a lot of them. But then again, maybe these are really low powered lasers and don't take much power at all. Anyone have any ideas or know anything about wires vs lasers?

Re:Power supply...

[Spy der Mann]

Maybe they do right now, but with today's nanotrends, expect nanoscopic lasers being used to transfer information in a chip.

I give it about 20 years. Maybe in 25 we'll start seeing fully-functional optical microprocessors. But by that time there will be already cold microprocessors using nanotube-based transistors, and running with perhaps an AA battery or something.

Re:Power supply...

[laughingcoyote]

I imagine the initial ENIAC-style transistor computers were power monsters too. So yes, they likely do, but technology only gets better with time. And in fact, depending how it's implemented, it may actually take a little LESS power once it reaches a production-quality level.

Re:Am I the only one that doesn't get it?

[thpr]

There are probably two major uses. The first is in an optical switch. Traditionally, switches were OEO (optical-electrical-optical) until the all-optical craze hit in 2000. OOO (all optical) are (in theory) able to switch the light faster, which reduces latency, power usage, and lots of other things in the optical core of the network. However, if you eliminate the separate optics devices and can run the optics directly onto the semiconductor, OEO may be a lot more competitive (meaning cheaper). Go search LightReading for "OEO" or "OOO" to follow that debate (of whether there is benefit to all-optical and the current state of the art. [Infinera is a rather interesting startup driving OEO into the future to compete with OOO]

The second major use would be chip-to-chip interconnect. However, this becomes a challenge, as you try to keep a ribbon of fiber-optics (think 200-2000 strands) perfectly lined up with the lasers on the die. I'm not saying it can't be done, but it is one of the hurdles to face before it could be used that way in mass-produced systems like a PC. The theory goes that at about 1 foot per second, electrical propagation between chips is causing us lots of headaches. HyperTransport and other technologies make some advances to get around the plain limits, but there are still major problems with sending high-speed signals on circuit boards. Even if this can't help speed up absolute memory access time, it could help to improve throughput between memory and the processor, helping to avoid some of the single-threaded bottlenecks that led IBM and its partners to develop Cell

implement

[Anonymous Coward]

just curious, how would you implement this technology on an x86 board?

Re:Expensive?

[oliverthered]

Don't think, know.
google anyone...?

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