PhotonicComputing
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Researchers build optical transistor out of silicon, provide path to all-optical computing
The speed of light is the universal speed limit, so naturally, optical technologies appeal when trying to construct speedy computational devices. Fiber optics let us shoot data to and fro at top speed, but for the time being our CPUs still make their calculations using electronic transistors. Good news is, researchers from Purdue University have built an optical transistor out of silicon that can propagate logic signals -- meaning it can serve as an optical switch and push enough photons to drive two other transistors. It's constructed of a microring resonator situated next to one optical line that transmits the signal, and a second that heats the microring to change its resonant frequency. The microring then resonates at a specific frequency to interact with the light in the signal line in such a way that its output is drastically reduced and essentially shut off. Presto, an optical transistor is born. Before dreams of superfast photonic computers start dancing in your head, however, just know they won't be showing up anytime soon -- the power consumption of such transistors is far beyond their electronic counterparts due to the energy inefficient lasers that power them.
Researchers slow light to a "crawl," photonic computers imminent
While other divisions of NTT are trying to rev up data transmission rates as high as possible, others are trying to slow down the speed of light. This might seem like a Sisyphean task, but those Japanese scientists have done it -- researchers from the telco giant have just published a paper in the January edition of Nature Photonics showing that by using synthetic "photonic crystals," light can be slowed to 5.8 kilometers per second (it normally goes at about 300,000 kilometers per second). We ought to point out, though, that this isn't the first time that light has been slowed down so much, with a team at Harvard achieving the task last year by using ultra-cold Bose-Einstein condensates, and another study at Harvard showed in 2003 that light could be slowed all the way to 38 mph. Still, all of this research is another step forward in "photonic computing," which aims to use trapped light to usurp more traditional electron storage in traditional computer logic. We're sure that once this technology gets transferred to consumer-grade laptops (like, say in 2020), we'll be able to render 12-dimensional shapes in no time at all. [Image courtesy The Economist]Read - The RegisterRead - TechworldRead - New Scientist
