Intel laser breakthrough a boon for communication

SAN FRANCISCO: Researchers from Intel Corp. have created the first continuous laser beam using silicon components, a development the chip maker called a major scientific breakthrough that could herald significant advances in communications and medicine.

In a paper to be published in the journal Nature, Intel's Photonics Technology Laboratory reported a way to overcome the primary hurdle to using silicon as a medium for laser light, an effect in which electrons freed by the energy of passing photons absorb the light as it passes through.

Researchers at the world's largest maker of microchips overcame that problem -- called two-photon absorption -- by using a technique from the world of semiconductors: it created positive and negative regions around the path of the laser light, which "vacuum" away electrons and provide a clear road for the laser.

A continuous laser beam generated through silicon, which is transparent to infrared light, could overcome cost and size limitations in current lasers used in surgery and communications, which are made with more exotic and expensive materials, Intel said.

Bahram Jalali, a professor of electrical engineering at the University of California in Los Angeles who has also done work with silicon lasers, said Intel's laser holds promise as the basis for defense applications, as in infrared jamming devices to defend against heat-seeking missiles.

He added, however, that Intel's device, technically called a silicon Raman laser, would not make a good replacement for other, more common laser applications.

"It is important to understand that the silicon Raman laser is not a replacement for existing diode lasers, such as the ones used in DVD players and telecom equipment," Jalali said. "Instead, it is a device that extends their operating range to longer wavelengths."

Mario Paniccia, the director of the photonics lab, said the device could have medical applications in the years ahead, replacing large lasers used for surgery that cost as much as $50,000 each with far less expensive and smaller devices.

Paniccia said Intel is aiming to create products from its work in silicon photonics by the end of the decade.

Last February, Intel reported on a way to use the silicon building blocks of computer chips to switch light on and off at high speeds. The silicon modulator took in laser light and pulsed it onto fiber-optic cables at very high speeds.