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New Material Could make for Terahertz-Speed Optical Switching

Insulator switches to conductor in just 2 picoseconds

2 min read

23 March 2005--Light may move fast, but it generally takes its time to change a material's electrical properties. But now a Franco-Japanese team has turned an insulator into a conductor in just 2 picoseconds, a 50-fold speedup that should catapult optical switching from the gigahertz to the terahertz range.

"This is very meaningful for device applications," says Ying Fu, a researcher in optoelectronics at the Chalmers Institute of Technology in Gothenburg, Sweden. "In this experiment, the switching is very clear--the signal-to-noise ratio is very large."

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The Transistor at 75

The past, present, and future of the modern world’s most important invention

2 min read
A photo of a birthday cake with 75 written on it.
Lisa Sheehan

Seventy-five years is a long time. It’s so long that most of us don’t remember a time before the transistor, and long enough for many engineers to have devoted entire careers to its use and development. In honor of this most important of technological achievements, this issue’s package of articles explores the transistor’s historical journey and potential future.

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