Global Sources
EE Times-Asia
Stay in touch with EE Times Asia
EE Times-Asia > Controls/MCUs

Researchers build 'first' hybrid silicon laser

Posted: 01 Nov 2006 ?? ?Print Version ?Bookmark and Share

Keywords:hybrid silicon laser? silicon photonics? Intel? UCSB?

Intel Corp. and University of California, Santa Barbara (UCSB) researchers last September announced what they claimed was the world's first electrically powered hybrid silicon laser, which can produce terabit-level optical computer data pipes and high-performance computing applications.

Using standard silicon manufacturing processes, researchers combined the light-emitting properties of Indium Phosphide (InP) with the light-routing capabilities of silicon into a single hybrid chip. When voltage is applied, light generated in the InP enters the silicon waveguide to create a continuous laser beam that can be used to drive other silicon photonic devices.

"We're seeing the beginning of driving low-cost technologies and new applications arising," said Mario Paniccia, Intel photonics technology lab director. "I'm excited that this latest development of laser has solved and addressed an issue that we've been struggling with for many yearsthat is, how to come up with a low-cost laser that we can attach with silicon photonics."

Bringing new apps
"We can drive the costs down 10 times for the same performance," said Dr. John Bowers, a UCSB professor working on InP for almost 30 years. "By doing that, our belief is that we'll actually open up a host of new applications and speed up the use of photonics in the communications world beyond wireless today."

This breakthrough technology paves the way for the production of low-cost, high-bandwidth silicon photonic devices for future computers and data centers. Moreover, Paniccia believes it will "drive optical technology throughout the world." He also envisions new systems and architectures based on optical communication in the future.

"Other applications are biochips, laboratory-on-a-chip and lasers as spectroscopic elements to analyze chemicals or cells," Bowers said. The new technology can also be used in fiber-to-the-home (FTTH). "One exciting development going on that's very cost-sensitive is FTTH, which today drives Asia in particular," Bowers continued. He believes that with the new process and volume, "we can drive FTTH costs down dramatically."

'Siliconizing' photonics
Paniccia said the vision of silicon photonics is "to bring volume economics to the optic communication industry." His group started with research and building photonic devices using standard silicon and manufacturing technologies to enable high-volume yield on a silicon wafer.

"Siliconizing" photonics, Paniccia said, involves six essential basic blocks. The first is a light source, "somewhere to generate light in which we can transmit data." The second is devices that would guide, route, split and direct light on the silicon chip. The third is a modulator for encoding or modulating data into the optical signal. The fourth is a photodetector that would convert photons back into electrons. Packaging is the fifth building block, involving low-cost and high-volume assembly methods. Intelligence completes the list of essentials for "siliconizing" photonics, or "using electronics to drive photonics."

A low-temperature oxygen plasma is key to manufacturing the device. It creates a thin oxide layer (about 25 atoms thick) on the surfaces of InP-based material and silicon. When heated and pressed together, the oxide layer works as a "glass-glue" that fuses the two materials into a single chip.

Researchers combined the light-emitting properties of Indium Phosphide (InP) with the light-routing capabilities of silicon into a single hybrid chip.

Microprocessor analogy
Paniccia said this hybrid silicon laser is still far from becoming a commercial product. However, he believes that "we may be able to see something like this technology in the early part of the next decade."

He took the analogy of the microprocessors. "Today, we're shipping processors that have nearly 2 billion transistors in a single chip. In 1960, the first demonstration was with two or three," he explained. "If you look at silicon photonics today, we are now in the early stages of starting to get the individual devices functioning, and we're beginning to integrate different photonic building blocks together."

Just like microprocessors, silicon photonics are expected to gain momentum in the coming years. "Now that you have these devices, you can start integrating these devices to come up with entirely new functions, new form factors, power and size that don't exist today."

Over time, he said, "we'll slowly see tens of devices, then hundreds and thousands of photonic devices. The devices will continue to shrink. You'll be able to integrate more devices together."

The first electrically-pumped hybrid silicon laser is among Intel's accomplishments in its long-term efforts to "siliconize" photonics using standard silicon manufacturing processes. In 2004, Intel researchers introduced a silicon-based optical modulator with a bandwidth of more than 1GHz, which was over 50 times faster than previous demonstrations of modulation in silicon. Last year, the researchers also demonstrated a laser-on-a-chip using standard CMOS silicon, amplifying light using an external light source based on the "Raman Effect."

- Maria Cecilia Carpena
Electronic Engineering Times-Asia

Article Comments - Researchers build 'first' hybrid sil...
*? You can enter [0] more charecters.
*Verify code:


Visit Asia Webinars to learn about the latest in technology and get practical design tips.

Back to Top