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Topic Name: Photonics: silicon reaches 200 gigabits per second
Category: Electronics
Research persons: Jean-Luc Goudet
Location: paris, France
Details
A liaison purely optical data transmission at heart of a computer, or even a processor: Intel is continuing this research for several years with the idea to run a little convenient material, but cheap and well-known silicon. A first success has been announced.
To provide high-speed data within a computer, a circuit or a greater distance, fiber optics is the ideal way. With rates still higher required heart of a processor for example, the copper may soon no longer keep pace. But these devices have their limits and expensive. Several laboratory in the world, including at Intel and IBM, bent over the years to use silicon.
This material has a major defect, that of not being transparent. It is therefore surprising to make it a candidate for photonics, this technique is to use light flux to carry information, or to treat it. But silicon, the element so abundant on our planet, so easy to extract (just a shovel sand ...), so cheap and so well known to the electronics industry has really great attractions.
In digging Waveguide in this material, Intel team led by Mario Paniccia had come to him to transport the light at high speed. The next problem was to make the interface between electronics and light transmission (or photonics), which has two elements. The first is the modulator, which transforms the information in the form of an electrical pulse light. This function is that of a laser. At the other end of the transmission, the second element, a photodetector, does the work Conversely, generating an electric current to flow from photons.
Soon a Tb / s?
After testing the possibility of a modulator combining silicon and indium, the team had made last year a prototype photonic modulator capable of transmitting 40 gigabits per second (Gbps). A little later, scientists Intel showed a photodetector capable, too, to analyze a luminous flux at a rate of 40 Gb / s. A new prototype modulator has just been introduced, working ... to 25 Gb / s. The rate is lower, but the circuit has eight elements, representing a total capacity of 200 Gb / s.
This value, however, remains theoretical because during the tests that have just been presented, the team has been running one channel at a time. The result with eight active elements must be verified because it is possible that interference phenomena occur, reducing performance.
By
Jean-Luc Goudet
Futura-Sciences
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