Laser Switches Insulator to Conductor and Back in Femtoseconds

Ultrashort pulses of light could lead to petahertz-speed computing

3 min read
Laser Switches Insulator to Conductor and Back in Femtoseconds
Photo: Thorsten Naeser, LMU

11 December 2012—The best transistors today can switch on and off hundreds of billions of times a second. But laser pulses can be more than 10 000 times as quick. Now researchers in Germany have used such ultrashort laser pulses to induce current with the same kind of frequencies—creating an electric switch with laser speed. 

“Laser pulses are the shortest signal you can generate,” says Martin Schultze, a researcher at the Max Planck Institute of Quantum Optics, in Garching, Germany, who was involved in the work and is currently a visiting scientist at the University of California, Berkeley. “They are much faster than anything electronic.” 

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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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