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Terahertz Waves

December 27, 2012

Terahertz waves, which could greatly improve scanning, imaging, and communication, just got a lot more practical.



Shrinking see-through scanners.  I’m Bob Hirshon and this is Science Update.

High-frequency terahertz waves can create sharp images of concealed objects, without the dangerous ionizing radiation of x-rays.  But until now, they’ve required bulky, expensive equipment in carefully controlled environments.  Now, Cal Tech electrical engineer Ali Hajimiri and his colleagues have found a way to generate a powerful terahertz signal from a microchip.  It involves coordinating the chip’s many transistors.

ALI HAJIMIRI (California Institute of Technology):

We came up with a way of making these transistors work in concert, together, each one of them contributing a little bit, but overall, collectively, they can generate and radiate the power.

Hajimiri says terahertz waves are not only a better and safer alternative to x-rays, but they also have other applications, like detecting cancer cells and chemical traces of bombs or drugs. I’m Bob Hirshon for AAAS, the Science Society.

A terahertz scanner, which now fits on a silicon chip, can detect hidden objects like this bullet and knife blade inside a stuffed toy. (Kaushik Sengupta/Caltech)

Location and frequency range of Terahertz waves in the electromagnetic spectrum (Tatoute/Wikipedia)