In this age of superfast fiber-optic Internet cables, slowness is still an issue. Light -- or photons -- traveling through the cables and carrying data have to be converted into electrons once they reach the computer. This not only takes time, the components that do the conversation take up space. The result: a huge bottleneck. On top of that the conversion is one more point at which hackers can eavesdrop on data.

But now a team at Purdue University has built a tiny optical diode that eliminates the need for conversion altogether and could allow computers to process the photons as data the way they currently process electrons.

Until now, it's been difficult to build a computer chip that can process photons as data. There has been quite a bit of design and conceptual work going on in this area, but many of the designs would require exotic manufacturing techniques and factory retooling.

Minghao Qi and Andrew Weiner and their team made a diode made from silicon, a material already familiar to silicon manufacturers. In their design, infrared light from a laser (typical of a fiber-optic connection) goes through an optical fiber and is guided by a structure called a waveguide. It then passes sequentially through two silicon rings. Depending on which ring the light enters first, it will either pass in the forward direction or be dissipated backward, which creates one-way transmission.  

Equally important, the new diodes can be built into existing chips with existing equipment. No new materials are necessary, as the rings are silicon on a silicon dioxide substrate. Qi told Discovery News that the group could make the ring up to 10 times smaller than its current size -- about 10 micrometers across. But even at larger sizes, adding the ability to process photons would save a lot of space, because the components that translate from photons to electrons are no longer necessary.