U.S. engineers say they've moved a step closer to creating computers that work at the speed of light, using light beams instead of electrons to manipulate and send data.
Researchers at the University of Utah say they've created the smallest-ever beamsplitter, a device that can divide a light beam into two distinct and separate channels, each of which can carry information.
The development brings computer designers one step closer to creating silicon photonic chips using light rather than electronics, which could yield next-generation computers and other mobile devices that could compute at speeds millions of times more quickly than current machines, they say.
"Light is the fastest thing you can use to transmit information," says computing and electrical engineering professor Rajesh Menon. "But that information has to be converted to electrons when it comes into your laptop."
Fiber-optic networks use light photons to move information over the Internet, but the conversion into electrons by a router or computer slows the flow of data, he explains.
That's why researchers have been working to eliminate the bottleneck, he says.
"The vision is to do everything in light."
In pursuit of that goal, the Utah engineers have created a polarization beamsplitter on a silicon chip that splits a guided incoming stream of light into two separate components, each one a data stream.
Most previous beamsplitters have been about 100-by-100 microns in size; the Utah version, designed using a new algorithm, is just 2.4-by-2.4 microns, around a 50th the width of a human hair, the researchers report in Nature Photonics.
At that size it could be possible to put millions of beamsplitters on a single chip, all directing light - and its data - in specific ways, the researchers say.
In addition to improving computing speed, a beamsplitter of that design could be inexpensive to produce as it uses common fabrication techniques already in place for making silicon chips, they add.
"Our vision is to create a library of ultracompact devices (including beamsplitters) that can then be all connected together in a variety of different ways to enable both optical computing and communications," Menon says.
Supercomputers utilizing silicon photonics are already being developed by companies such as IBM and Intel, but those first-generation machines will use hybrid processors that are still partially electronic, Menon notes.
The University of Utah beamsplitters could be available for use in those computers in about 3 years, he says.
