Marc's 2nd Blog

Breakthrough: Intel builds laser using silicon
Associated Press

SANTA CLARA, Calif. - In an advance that could drive down the cost of optical networks, researchers have built a laser using silicon, the same material used in computer chips, that shines without stopping or blinking.

The technology could have important uses, Intel Corp. researchers said. It could be used to make high-bandwidth, light-based communications inexpensive enough to replace copper wire inside computers, and could reduce the cost of lasers used in medicine, defense and other industries.

The research is published in Thursday's issue of the journal Nature.

Until recently, few experts thought humble silicon could be used to build a laser, said Mario Paniccia, director of Intel's photonics lab. It tends to absorb light energy, dissipating it as heat rather than amplifying it as current lasers, which use more exotic materials, do.

"This is a fundamental breakthrough," said Paniccia, a co-author of the Intel study. "It's one of those things that's a game changer."

Intel researchers had already announced in January that they had built an all-silicon laser. But that device had a problem: The laser effect stopped after a time. A solution to that problem resulted in laser light that came in pulses -- impractical for most uses. Now, they have built in a tiny component that eliminates that problem.

"That was a major remaining milestone for these lasers," said Bahram Jalali, a University of California, Los Angeles electrical engineering professor who was not involved in the Intel research.

Laser beams are usually created by using a blast of electricity or light to boost the energy levels of electrons in the atoms of a crystal, semiconductor or gas. The electrons then release photons, the basic element of light, which can be formed into a concentrated beam.

That process doesn't work with silicon, so the researchers focused on a weak scattering of photons called the "Raman effect," which is already in use in one type of laser. They found the Raman effect is 10,000 times stronger in silicon.
HoustonChronicle.com - Breakthrough: Intel builds laser using silicon