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Silicon Is Key to Quest for $5 LED Lightbulb

Bridgelux process grows gallium-nitride on high-volume silicon wafers

3 min read

The LED lightbulb has loads to recommend it. Compared to the compact fluorescent, it can be twice as efficient, lasts far longer, and is free of mercury. But high prices are holding back sales: A 40-watt-equivalent LED bulb with a good hue starts at around US $20, and 60-W versions retail for far more.

The good news is that this barrier to mass adoption should fall in the next two to three years, thanks to recent developments by the LED maker Bridgelux that should spur the launch of a $5 bulb. This California-based firm plans to slash the price of white emitting chips—which account for up to 70 percent of the cost of this type of bulb—by churning out millions of gallium nitride LEDs on 200-millimeter-diameter silicon wafers.

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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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