Intel's silicon has designs on optical applications
Researchers at Intel have unveiled a silicon test chip that can encode 200Gbps on a beam of light. In contrast, the most advanced chips used in today's fastest optical networks operate at speeds of 100Gbps. And these 100-gigabit chips, which are made from nonsilicon materials, have limitations that Intel's chip doesn't as they can't scale to faster speeds as inexpensively as silicon can.
Silicon is often overlooked in the photonics industry because its optical properties are inferior to those of gallium, indium and germanium, which produce, detect, and manipulate photons. But within the past few years,Intel optical engineers have worked on silicon, engineering around some of its natural limitations.
The new Intel test chip splits an incoming beam of light into eight channels. Within each channel is a modulator, a device that encodes data onto light. After the beams are encoded with data, they are recombined. In the tests, each modulator ran at a rate of 25Gbps, and each performed nearly identically, says Mario Paniccia, director of the company's silicon-photonics lab. He notes that only one modulator was tested at a time but says that in a future paper his team will publish the results from running multiple channels simultaneously. Multiple channels could produce cross talk. that could hinder performance. But in preliminary results, Paniccia says, the design limits cross talk.
In 2004, Intel researchers, led by Paniccia, proved that silicon could be used to build a 1Gbps modulator; in 2005, the team boosted the speed to 10Gbps. Also in 2005, the researchers built a remarkably good all-silicon laser, and in 2006, they introduced a hybrid laser that combines InP with silicon, allowing a practical telecom laser to be fabricated on a silicon wafer. Most recently, they have speeded up the modulator to 40Gbps and built a silicon detector.
Source: http://www.technologyreview.com