Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Stanford breakthrough heralds super-efficient light-based computers

28.05.2015

Light can transmit more data while consuming far less power than electricity, and an engineering feat brings optical data transport closer to replacing wires

Stanford electrical engineer Jelena Vuckovic wants to make computers faster and more efficient by reinventing how they send data back and forth between chips, where the work is done.


Infrared light enters this silicon structure from the left. The cut-out patterns, determined by an algorithm, route two different frequencies of this light into the pathways on the right. This is a greatly magnified image of a working device that is about the size of a speck of dust.

(Photo: Alexander Piggott)

In computers today, data is pushed through wires as a stream of electrons. That takes a lot of power, which helps explain why laptops get so warm.

"Several years ago, my colleague David Miller carefully analyzed power consumption in computers, and the results were striking," said Vuckovic, referring to electrical engineering Professor David Miller. "Up to 80 percent of the microprocessor power is consumed by sending data over the wires - so called interconnects."

In a Nature Photonics article whose lead author is Stanford graduate student Alexander Piggott, Vuckovic, a professor of electrical engineering, and her team explain a process that could revolutionize computing by making it practical to use light instead of electricity to carry data inside computers.

Proven technology

In essence, the Stanford engineers want to miniaturize the proven technology of the Internet, which moves data by beaming photons of light through fiber optic threads.

"Optical transport uses far less energy than sending electrons through wires," Piggott said. "For chip-scale links, light can carry more than 20 times as much data."

Theoretically, this is doable because silicon is transparent to infrared light - the way glass is transparent to visible light. So wires could be replaced by optical interconnects: silicon structures designed to carry infrared light.

But so far, engineers have had to design optical interconnects one at a time. Given that thousands of such linkages are needed for each electronic system, optical data transport has remained impractical.

Now the Stanford engineers believe they've broken that bottleneck by inventing what they call an inverse design algorithm.

It works as the name suggests: the engineers specify what they want the optical circuit to do, and the software provides the details of how to fabricate a silicon structure to perform the task.

"We used the algorithm to design a working optical circuit and made several copies in our lab," Vuckovic said.

In addition to Piggott, the research team included former graduate student Jesse Lu (now at Google,) graduate student Jan Petykiewicz and postdoctoral scholars Thomas Babinec and Konstantinos Lagoudakis. As they reported in Nature Photonics, the devices functioned flawlessly despite tiny imperfections.

"Our manufacturing processes are not nearly as precise as those at commercial fabrication plants," Piggott said. "The fact that we could build devices this robust on our equipment tells us that this technology will be easy to mass-produce at state-of-the-art facilities."

The researchers envision many other potential applications for their inverse design algorithm, including high bandwidth optical communications, compact microscopy systems and ultra-secure quantum communications.

Light and silicon

The Stanford work relies on the well-known fact that infrared light will pass through silicon the way sunlight shines through glass.

And just as a prism bends visible light to reveal the rainbow, different silicon structures can bend infrared light in useful ways.

The Stanford algorithm designs silicon structures so slender that more than 20 of them could sit side-by-side inside the diameter of a human hair. These silicon interconnects can direct a specific frequency of infrared light to a specific location to replace a wire.

By loading data onto these frequencies, the Stanford algorithm can create switches or conduits or whatever else is required for the task.

The inverse design algorithm is what makes optical interconnects practical by describing how to create what amount to silicon prisms to bend infrared light.

Once the algorithm has calculated the proper shape for the task, engineers can use standard industrial processes to transfer that pattern onto a slice of silicon.

"Our structures look like Swiss cheese but they work better than anything we've seen before," Vuckovic said.

She and Piggott have made several different types of optical interconnects and they see no limits on what their inverse design algorithm can do.

In their Nature photonics paper, the Stanford authors note that the automation of large-scale circuit design enabled engineers to create today's sophisticated electronics.

By automating the process of designing optical interconnects, they feel that they have set the stage for the next generation of even faster and far more energy-efficient computers that use light rather than electricity for internal data transport.

Media Contact

Tom Abate
tabate@stanford.edu
650-736-2245

 @stanfordeng

http://soe.stanford.edu 

Tom Abate | EurekAlert!

More articles from Information Technology:

nachricht Ultra-precise chip-scale sensor detects unprecedentedly small changes at the nanoscale
18.01.2017 | The Hebrew University of Jerusalem

nachricht Data analysis optimizes cyber-physical systems in telecommunications and building automation
18.01.2017 | Fraunhofer-Institut für Algorithmen und Wissenschaftliches Rechnen SCAI

All articles from Information Technology >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: How gut bacteria can make us ill

HZI researchers decipher infection mechanisms of Yersinia and immune responses of the host

Yersiniae cause severe intestinal infections. Studies using Yersinia pseudotuberculosis as a model organism aim to elucidate the infection mechanisms of these...

Im Focus: Interfacial Superconductivity: Magnetic and superconducting order revealed simultaneously

Researchers from the University of Hamburg in Germany, in collaboration with colleagues from the University of Aarhus in Denmark, have synthesized a new superconducting material by growing a few layers of an antiferromagnetic transition-metal chalcogenide on a bismuth-based topological insulator, both being non-superconducting materials.

While superconductivity and magnetism are generally believed to be mutually exclusive, surprisingly, in this new material, superconducting correlations...

Im Focus: Studying fundamental particles in materials

Laser-driving of semimetals allows creating novel quasiparticle states within condensed matter systems and switching between different states on ultrafast time scales

Studying properties of fundamental particles in condensed matter systems is a promising approach to quantum field theory. Quasiparticles offer the opportunity...

Im Focus: Designing Architecture with Solar Building Envelopes

Among the general public, solar thermal energy is currently associated with dark blue, rectangular collectors on building roofs. Technologies are needed for aesthetically high quality architecture which offer the architect more room for manoeuvre when it comes to low- and plus-energy buildings. With the “ArKol” project, researchers at Fraunhofer ISE together with partners are currently developing two façade collectors for solar thermal energy generation, which permit a high degree of design flexibility: a strip collector for opaque façade sections and a solar thermal blind for transparent sections. The current state of the two developments will be presented at the BAU 2017 trade fair.

As part of the “ArKol – development of architecturally highly integrated façade collectors with heat pipes” project, Fraunhofer ISE together with its partners...

Im Focus: How to inflate a hardened concrete shell with a weight of 80 t

At TU Wien, an alternative for resource intensive formwork for the construction of concrete domes was developed. It is now used in a test dome for the Austrian Federal Railways Infrastructure (ÖBB Infrastruktur).

Concrete shells are efficient structures, but not very resource efficient. The formwork for the construction of concrete domes alone requires a high amount of...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

12V, 48V, high-voltage – trends in E/E automotive architecture

10.01.2017 | Event News

2nd Conference on Non-Textual Information on 10 and 11 May 2017 in Hannover

09.01.2017 | Event News

Nothing will happen without batteries making it happen!

05.01.2017 | Event News

 
Latest News

A big nano boost for solar cells

18.01.2017 | Power and Electrical Engineering

Glass's off-kilter harmonies

18.01.2017 | Materials Sciences

Toward a 'smart' patch that automatically delivers insulin when needed

18.01.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>