Laser Chips For Light Speed Communications

Hi SearchFreaks

Here is a good news for Technology Freaks.

From decades engineers have tried to accelerate the pace of conventional, electricity-based computer chips by melding them with laser-based signal processors.

Researchers at the University of California, Santa Barbara (UCSB), have designed a silicon-based laser that emits ultrashort pulses of light at high frequencies--two characteristics that are crucial if silicon-based lasers are to become practical. Eventually, the researchers hope that the new laser could replace other, more expensive lasers in optical communication networks. It could even lead to faster computers that shuttle data around using light instead of electricity.

Modern telecommunications networks use three distinct gadgets--lasers, modulators, and detectors--to produce, encode, and detect light. Currently, all three are made of nonsilicon semiconductors, such as Indium Phosphide, that are difficult to mass-produce; as a consequence, they tend to be expensive and bulky. But if they could instead be made from silicon, they could be integrated on individual chips, says John Bowers, professor of electrical and computer engineering at UCSB. Devices that currently cost hundreds of dollars each could then be made in bulk for pennies, and the cost of bandwidth would plummet. The one snag in the plan is that it's hard to make silicon produce light.

To turn the laser on, the researchers applied electrical current to metal contacts on top of the indium Phosphide. Indium Phosphide is a naturally light-emitting material, so the strips of it on top of the wafer produced photons that got trapped in the channel below, bouncing back and forth along the length of the silicon waveguide. In certain materials, that bouncing is enough to amplify normal light into laser light, but not in silicon.

The corporate and university teams set out to develop a hybrid design that could handle both electricity and light. They bonded a thin layer of Indium Phosphide, a compound that acts as a medium for the Laser, onto Silicon sheets by exposing both materials to a blast of hot, electrically charged oxygen atoms, the Indium Phosphide was spiked with Aluminum Gallium Indium Arsenide to give it added speed. A microlayer of oxides then formed on the surface, gluing them together. “ We can make thousands of Laser with just one bond, as opposed to bonding each Laser individually,” says John Bowers of University of California, Santa Barbara.

News Courtesy : www.technologyreview.com/Infotech/

To view the University of California Santa Barbara, Home Page and know more about Academic, Research, Admissions at University of California Santa Barbara

Click Link: http://www.ucsb.edu/

To Know more about John E. Bowers Professor Click this Link http://www.ece.ucsb.edu/uoeg/professor_bowers/

Also see the Optoelectronics Research Group by John Bowers of University of California Santa Barbara. Here is the Link: http://www.ece.ucsb.edu/uoeg/

Yours Searchfreak.