First Silicon Laser

An anonymous reader writes "Since the creation of the first working laser, scientists have fashioned them from substances ranging from neon to sapphire. Silicon was not considered a candidate, because its structure wouldn't allow for the proper line-up of electrons needed to get this semiconductor to emit light. That has now changed thanks to three researchers at Brown University who have created the first directly pumped silicon laser by drilling billions of holes in a small bit of silicon using a nanoscale template."

Comments

Do you hear that?

[chriswaclawik]

That's the sound of a thousand slashdotters trying to make a "shark with friggin laser beams" joke before I do.

Which one is first?

[TechyImmigrant]

Another first silicon laser? So who was really first?

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http://oemagazine.com/newscast/2004/102604_newscas t01.html

Los Angeles, CA | 26 October 2004 -- Researchers at UCLA have demonstrated the first silicon laser, which could lead to more effective biochemical detection, secure communications, and defense against heat-seeking missiles.

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http://www.intel.com/technology/silicon/sp/

First Continuous Silicon Laser

In a paper published February 17, 2005 by the prestigious scientific journal Nature, Intel researchers disclosed the development of the first continuous wave all-silicon laser using a physical property called the Raman Effect. They built the experimental device using Intel's existing standard CMOS high-volume manufacturing processes. This is the third silicon photonics paper Intel has published in Nature since 2004, beginning with the modulator breakthrough (see the Learn More section).

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http://www.photonics.com/readart.asp?url=readartic le&artid=325&bhsh=1050&bhsw=1680&bhqs=1

PROVIDENCE, R.I., Nov. 21 -- Silicon has made its way into everything from computers to cameras. But a silicon laser? Physically impossible -- until now. A Brown University research team led by Jimmy Xu has engineered the first directly pumped silicon laser by changing the structure of the silicon crystal through a novel nanoscale technique.

Re:Which one is first?

[Hal-9001]

• The UCLA laser was a Raman laser that could only operate in pulsed mode. The Raman effect is a nonlinear effect that requires several external laser beams to power the silicon device.
• The Intel laser was also a Raman laser and was the first silicon Raman laser that could operate in continuous-wave (non-pulsed) mode.
• The Brown laser is not a Raman laser. Therefore it only requires a single external laser beam to power the device.

The holy grail, of course, is an electrically-pumped silicon laser where you apply a voltage directly across the device and get laser light out. We're not there yet, but each of these devices represents progress toward that goal. In particular, a device with direct optical pumping like the Brown laser suggests that direct electrical pumping might not be far off.

Re:Anyone care to explain the significance of this

[Ungrounded Lightning]

Currently, putting a practical laser on a chip means using a semiconductor other than silicon, such as gallium arsenide. But silicon has better properties for making large complex circuits - and the technology of doing so is more advanced on silicon than on other semiconductor materials.

This means that when you want to hook up a laser to a logic circuit you end up with two separate chips and interconnections between them (or maybe with a separate layer of the lasing semiconductor grown onto a silicon chip.) This is a major hassle and expensive. It also costs a surprising amount of power to drive high-speed signals through the connection between the two chips.

If it were possible to build the lasers on, and out of, the silicon chip itself it would drastically decrease the cost and power consumption of the resulting devices.

Beyond this, it would be an enabling technology: It costs even more power to push signals between one silicon chip and another across a board or backplane. It would be nice to use a laser and optic fiber to make the connection. But why bother if you still have to spend the power to get the signal through the wiring from the silicon to a separate laser that generates the light? If you could put the laser on the silicon chip and save the power you could replace (at least) the critical high-speed wiring between chips with fibers, drastically increasing speed and cutting power.

Up to now it hasn't been possible to get silicon to lase directly (although there has been some recent work with nanoscale laser structures grown on its surface.) Now they've found a way to do it.

It isn't ready for prime time yet, by a long shot. But it's the initial crack in the wall, and breaking down this wall is a BIG DEAL. So researchers will be jumping on this. You might see additional breakthroughs and practical applications in shorter order than with other new technology breakthroughs.

If they get it working efficiently in the region between room temperature and near boiling point where silicon chips normally operate you'll get another increment in processor speed/power/size tradeoffs.

It's a way to sidestep yet another of the long string of roadblocks that have threatened to knock us off the Moore's Law curve.