How arming microprocessors with lasers could change the game

7 Jun 2016

Prism image via Wikimedia Commons

An international team of scientists has found a way to make microprocessors faster, while using less power. The secret? Arming them with tiny lasers.

Faster and less power hungry: that’s the general gist of computing evolution.

PCs that used to take up an entire alcove in your living room are now outperformed by ultra-thin laptops. Clunky Nokia 3210s couldn’t last a second in the ring with an iPhone.

This, invariably, boils down to processing performance, which, in turn, is based on microprocessors – the brains of today’s dominant machines.

An international achievement

Scientists are continually striving for faster and less power-hungry machines. The problem is both of these things are conceptive and follow an interminable drive for improvement – it’s a never-ending pursuit.

However, sometimes the leaps made are worth noting, which brings us to tiny lasers. Scientists from the Hong Kong University of Science and Technology (HKUST), the University of California, Santa Barbara, Sandia National Laboratories and Harvard University were able to fabricate tiny lasers directly on silicon.

Doing this is a major first as, for decades now, people have struggled to work out how to match up silicon with lasers successfully.

But, by integrating sub-wavelength cavities onto silicon, they were able to create and demonstrate high-density, on-chip, light-emitting elements.

Photonics and microprocessors

“Putting lasers on microprocessors boosts their capabilities and allows them to run at much lower powers, which is a big step toward photonics and electronics integration on the silicon platform,” said Prof Kei May Lau of HKUst.

One issue, though, is the lasers’ size. Typically 1mmx1mm, in this instance, the lasers were only one micron in diameter – translation: very, very small. This should make them less suited to power transfers.

But the scientists used “tiny whispering gallery mode lasers that are 1,000 times shorter in length, and one million times smaller in area than those currently used”, said Lau.

This means Lau and the rest of the team have potentially answered the call of companies that rely on major data communications transfers.

“Photonics is the most energy-efficient and cost-effective method to transmit large volumes of data over long distances,” said Lau, noting that light sources in this regard were previously ‘off-chip’, not present on the component.

“Our work enables on-chip integration of lasers, an [indispensable] component, with other silicon photonics and microprocessors.”

Gordon Hunt was a journalist with Silicon Republic