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Quantum Dots Enhance LED Lighting

Tiny semiconductor crystals could produce better colors for lighting and computer displays

3 min read
Quantum Dots Enhance LED Lighting

9 December 2009—The next big thing in solid-state lighting may be exceedingly tiny—the quantum dot. Researchers from around the world gathered at the Materials Research Society fall meeting in Boston last week to discuss the progress they're making in using quantum dots to enhance the color and efficiency of light-emitting diodes (LEDs).

Quantum dots are nanometer-size bits of semiconductor material, such as cadmium selenide, that fluoresce when excited by photons or electrons. By choosing a certain material and a certain size, researchers can precisely tune the wavelength of light emitted. In general, a dot that's 2 nanometers in diameter emits blue light, a 4-nm dot emits green, and a 6-nm dot emits red.

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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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