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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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Two Startups Are Bringing Fiber to the Processor

Avicena’s blue microLEDs are the dark horse in a race with Ayar Labs’ laser-based system

5 min read
Diffuse blue light shines from a patterned surface through a ring. A blue cable leads away from it.

Avicena’s microLED chiplets could one day link all the CPUs in a computer cluster together.


If a CPU in Seoul sends a byte of data to a processor in Prague, the information covers most of the distance as light, zipping along with no resistance. But put both those processors on the same motherboard, and they’ll need to communicate over energy-sapping copper, which slow the communication speeds possible within computers. Two Silicon Valley startups, Avicena and Ayar Labs, are doing something about that longstanding limit. If they succeed in their attempts to finally bring optical fiber all the way to the processor, it might not just accelerate computing—it might also remake it.

Both companies are developing fiber-connected chiplets, small chips meant to share a high-bandwidth connection with CPUs and other data-hungry silicon in a shared package. They are each ramping up production in 2023, though it may be a couple of years before we see a computer on the market with either product.

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