Intel Takes Next Step in Developing Silicon Photonics

The company's researchers have now been able to produce bandwidth at 40 gigabits per second-a major step in bringing the technology closer to reality.

Researchers with Intel have moved a step closer toward integrating silicon chips and lasers in a new field the company calls silicon photonics— the process of creating on-chip components that can use light to transmit data.

On July 24, researchers with the Santa Clara, Calif., company announced that they had significantly increased the bandwidth with the help of a laser modulator that will now allow data to transmit at 40 gigabits per second. Previously, Intel had announced gear running at 10Gbps in its labs.

The next step, said Mario Paniccia, an Intel fellow and director of the companys Photonics Technology Lab, will be to use 25 of these silicon laser modulators, each working at 40Gbps, to produce a 1 terabit-per-second, high-speed optical link. A terabit equals 1,000 billion bits.

This latest development, Paniccia said, is an enormous step toward the companys goal of developing products built around silicon photonics technology, including practical uses inside enterprise data centers and also with telecommunications companies. The ability of the silicon laser modulators to reach 40Gbps now means that the technology can match the speed of the fastest modulators available in the market now.

So far, Intel and its researchers have not offered specific guidelines or road maps for products to be built using silicon photonics, although the company has said it has plans to incorporate some of the technology into commercial products by the end of the decade.

/zimages/3/28571.gifClick here to read more about Intels efforts to develop silicon photonics.

When Paniccia first began experimenting with silicon photonics, his labs were able to transmit data at only 1Gbps. The jump to 10Gbps and then to 40Gbps shows how far the companys research has come since those first days.

"The fact that were actually transmitting at 40 gigabits per second is an enormous leap forward in performance," Paniccia told eWEEK. "This development gives us an idea about what is happening now. Weve looked at the building blocks and proved that we can do this."

The laser modulator that Intel used to achieve 40Gpbs is smaller and consumes less power than the previous ones used to achieve 10Gbps. The modular is based on what Paniccia calls a traveling wave design that transmits the data.

Intels labs have been working for some time to develop silicon photonics as a replacement for traditional electrical interconnects, which use copper wiring to speed up the connections to move data to and from microprocessors.

Silicon photonics, however, is expensive and requires what Intel calls exotic materials to make this technological experiment a reality. The goal of the research is to develop photonic devices using silicon as the base material and use high-volume manufacturing processes that already exist at the companys fabs to help reduce the cost of bringing the technology to the commercial market.

/zimages/3/28571.gifClick here to read more about Intels new Ethernet controllers.

Intel also has a keen interest in this technology to develop high-bandwidth interconnects that can move more data. This is especially important for the companys development of multicore chips and its other experiments with what Intel calls "tera-scale" computing. Earlier this year, the company detailed its efforts behind developing an 80-core chip, although this remains a proof-of-concept design.

Eventually, researchers believe they will be able to develop an integrated silicon photonic chip that can be used to achieve the I/O needed to realize the full potential of the companys tera-scale computing efforts.

A more practical use for silicon photonic technology in the data center, Paniccia said, would be to connect servers to one another without the traditional constraints of cables currently used to link the backplanes of systems. Eventually, the technology could be used to achieve a connection between CPUs or between CPUs and memory, replacing traditional copper wiring.

On its way to scaling the laser modulators up to 1Tbps, Paniccia said researchers first will look to sustain performance at 100Gbps and 200Gbps.

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