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Identifying Explosives at a Distance

The random Raman laser is the lastest technology to detect explosives and other nasty stuff from a safe vantage

3 min read
A laser beam fired at a powder causes the powder itself to become a laser.
Random Raman Laser Light: A laser beam fired at a powder causes the powder itself to become a laser, beaming out information about the material’s molecular structure.
Photo: Brett Hokr

Being standoffish is usually frowned upon—that is, unless what you’re standing off from might be an explosive or a cloud of anthrax spores. That’s why efforts have accelerated to develop standoff detection techniques that use lasers to identify chemicals and biological substances from a safe distance.

The newest entry in the field is called random Raman spectroscopy. Shine a laser beam into a loose material—say, a powder—and if the density is right, the photons will bounce around among the powder’s particles until they stimulate a new laser emission. Such a random laser, as it is known, works much the same way as a more traditional laser cavity, only without mirrors.

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3D-Stacked CMOS Takes Moore’s Law to New Heights

When transistors can’t get any smaller, the only direction is up

10 min read
An image of stacked squares with yellow flat bars through them.
Emily Cooper
Green

Perhaps the most far-reaching technological achievement over the last 50 years has been the steady march toward ever smaller transistors, fitting them more tightly together, and reducing their power consumption. And yet, ever since the two of us started our careers at Intel more than 20 years ago, we’ve been hearing the alarms that the descent into the infinitesimal was about to end. Yet year after year, brilliant new innovations continue to propel the semiconductor industry further.

Along this journey, we engineers had to change the transistor’s architecture as we continued to scale down area and power consumption while boosting performance. The “planar” transistor designs that took us through the last half of the 20th century gave way to 3D fin-shaped devices by the first half of the 2010s. Now, these too have an end date in sight, with a new gate-all-around (GAA) structure rolling into production soon. But we have to look even further ahead because our ability to scale down even this new transistor architecture, which we call RibbonFET, has its limits.

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