Researchers herald optical-computing breakthrough

 

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By Stewart Mitchell

Posted on 18 Aug 2009 at 11:22

Researchers at Purdue University in the US have demonstrated a nano-laser that they claim will pave the way for photonic computers using light instead of electrons to process information.

The microscopic "spacer" device is described as a breakthrough in photonics technology because it is the first of its kind to emit visible light and represents a critical component for possible future technologies based on "nanophotonic" circuitry.

The development of nanophotonic circuits will ultimately require a laser-light source, but conventional lasers are limited in how small they can be made because a key component, the optical resonator, must be at least half the size of the wavelength of laser light.

The researchers claim they have overcome this hurdle by using not photons but surface plasmons, which enabled them to create a resonator just 44 nanometers, or billionths of a meter, in diameter.

We have demonstrated the nanolaser - essential for nanophotonics to become a practical technology

"Here, we have demonstrated the feasibility of the most critical component - the nanolaser - essential for nanophotonics to become a practical technology," says Vladimir Shalaev, professor of Electrical and Computer Engineering at Purdue University.

Although photonics in computing has been explored for some time – and has already filtered down into in data centres, where optical systems have replaced copper in some applications – the idea of squeezing photonics onto a chip remains a concept for the future.

According to the Purdue researchers, the next step in the quest for a working photonic computer will involve creating a spaser-based nanolaser that uses an electrical input source instead of a light source, which would make them more practical for computer and electronics applications.