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How Optical Circuits Will Keep Pushing Moore’s Law Toward Insanely Fast Chips

Light circuits will make your computer communicate internally and externally much quicker–and they’ll be smaller to boot!

How Optical Circuits Will Keep Pushing Moore’s Law Toward Insanely Fast Chips
[Image: Flickr user Vinoth Chandar]

Computers will only move as fast as their digital organs can talk to each other via electric current. Now researchers are looking into a shorter-wavelength–and therefore faster–solution: using light to transmit information instead of electricity.

Using a hyperthin array of nanoantennas, researchers have managed to shrink the wavelength of light to transfer data through a “metasurface” sheet thinner than any copper circuit. The bottom line: Science is making optical circuits a reality.

“If we moved to shorter wavelengths in the electromagnetic spectrum–like light–we could make things smaller, faster, and more efficient,” said University of Pennsylvania Professor Nader Engheta in 2012. The development of the light-controlling “metasurface” opens the door to transmission and processing of data inside chips using single photons (light particles) since conventional photonic devices cannot reduce the wavelength of light, which is naturally too large to fit in the tiny components needed for integrated circuits.

The Purdue scientists who developed the 30-nanometer wide “metasurface” shined a laser through it to project a hologram surface 10 microns above, displaying the word “Purdue” to a width of 100 microns–the width of a human hair.

Xingjie Ni, Birck Nanotechnology Center

Obviously, this has applications for digital and 3-D displays, especially with the hologram’s resolution of one-micron-wide letter strokes. But by simply tweaking the direction of the V-shaped nanoantennas that make up the metasurface, the researchers gained control over the intensity and phase/timing of light shined through the metasurface–which opens the door to bringing so-called “optical circuits” into operational use.

Other important thresholds have been breached in the last year, such as the creation of a polarizing filter that acts as a transistor to terahertz-wavelength light . There was even an optical circuit-lined cable, the Light Leak, that Intel planned to deploy that doubled USB 3.0’s transfer speed of 5 Mbps. Critics panned the higher cost and lack of need for 10 Mbps transfer rate back in 2010, which led Intel to find a cheaper copper method to attain those speeds–and Apple adopted the rebranded Thunderbolt cable for its fleet of devices. But back in September, Corning released the first optical versions of the Thunderbolt cables–which, while not able to provide power to devices like copper cables, can expand the 3m length limit of data-transferring copper-wired cords to 100m. They’re 80% lighter and 50% smaller in diameter to boot.