Electrons are so 20th century. When it comes to computing and communications in the new millennium, it’s all about photons. And a new development by the boffins over at semiconductor giant, Intel, has brought photons one step closer to a computer near you. Researchers at Intel’s Photonics Technology Lab have invented a new photodetector that promises to vastly increase the speed of data communications, and all at the cost of mass produced silicon chips.

Light is already used to transmit data over vast optic fibre networks – which form the backbone of the internet – but the trick is converting that light into electrons on the other end, so the data can be handled by conventional computer chips. Current optical detectors employ exotic materials like indium phosphate, which makes them difficult and expensive to manufacture. Furthermore, they’re limited in their sensitivity; with a traditional optical sensor, one photon goes in, one electron comes out.

The intention of the Intel technicians, led by Dr Mario Paniccia, was to “draft Moore’s Law”, which is the imperative that has driven the semiconductor industry to double its performance every 18-24 months over the past 30 years. To do this, they needed to build a sensitive photodetector using silicon. And this they did.

Not only does this enable them to build the photodetectors using conventional semiconductor manufacturing techniques, but they also harnessed a useful phenomenon called the ‘avalanche effect’. As the name suggests, this cascading reaction can take a small input and rapidly amplify it into a large output. So with Intel’s avalanche photodetector (APD), one photon goes in, and 10 to 100 electrons come out. The result is a tiny, inexpensive device with world record performance.

The initial application will be in fibre optic networks, where the APD can deliver one of two benefits. Because the APD is so much more sensitive than conventional photodetectors, it can be used on an optical link running at one tenth the power of a regular link. This means transmitters can be made smaller and cheaper, potentially integrating them into a wider range of networking devices. This could also make ultra high bandwidth fibre to the home a reality in the near future. Alternatively, with regular transmitters, the APD can operate over distances up to 10 times as great.

The APD could also provide a missing link in quantum cryptography, which requires very precise and sensitive photodetectors to receive its unbreakable messages. Intel is also exploring a two dimensional array of APD sensors for use as very sensitive optical security sensors, which can see beyond the visible spectrum and into the infra red. Finally, the APD could be integrated into biochips, which are like miniature chemical and biological laboratories on a single chip. All for the cost of peanuts… uh, silicon.

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