Graphene Device Modulates Light

Could speed up optical communications and bring them to computer chips

3 min read

9 May 2011—A device built out of graphene that can encode electrical signals onto light could dramatically increase the speed of optical communications and bring light-based data transfer down to the scale of computer chips, its creators say.

Such a device, called an optical modulator, has the potential to operate at speeds of 500 gigahertz and could be as small as a few square micrometers, say the researchers at the Nanoscale Science and Engineering Center at the University of California, Berkeley. That kind of speed makes for blazingly fast communications. "If you can connect to the Internet with 100 GHz, that means you can download a movie in a second," says Ming Liu, a postdoctoral researcher at Berkeley and lead author of a paper on the device; the paper appears in the 8 May advanced online publication of the journal Nature.

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A Circuit to Boost Battery Life

Digital low-dropout voltage regulators will save time, money, and power

11 min read
Image of a battery held sideways by pliers on each side.
Edmon de Haro

YOU'VE PROBABLY PLAYED hundreds, maybe thousands, of videos on your smartphone. But have you ever thought about what happens when you press “play”?

The instant you touch that little triangle, many things happen at once. In microseconds, idle compute cores on your phone's processor spring to life. As they do so, their voltages and clock frequencies shoot up to ensure that the video decompresses and displays without delay. Meanwhile, other cores, running tasks in the background, throttle down. Charge surges into the active cores' millions of transistors and slows to a trickle in the newly idled ones.

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