http://spectrum.ieee.org/cars-that-think/transportation/advanced-cars/driving-with-laser-headlights
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http://spectrum.ieee.org/cars-that-think/transportation/advanced-cars/driving-with-laser-headlights
Posted from WordPress for Android
4 Comments
Tomi Engdahl says:
SIL STRIKING POINT: Improved solid-state light sources will be key to the future of lighting
http://www.ledsmagazine.com/articles/2017/01/sil-striking-point-improved-solid-state-light-sources-will-be-key-to-the-future-of-lighting.html
Bob Steele: InGaN [indium gallium nitride] diode lasers have been around for a long time, and are widely used in consumer electronics products such as Blu-ray players. Why are they only now being considered for lighting?
SoraaLaser’s Paul RudyPaul Rudy: In recent years, a more advanced type of visible laser diode technology has been developed, largely at UC Santa Barbara, based on a material known as semipolar GaN.
Diode lasers based on this material have a 3-5X higher gain compared to more conventional c-plane InGaN laser diodes. This high gain, along with design freedom such as aluminum-free structures, enables higher power and higher efficiency InGaN lasers. From the applications perspective, high-power blue lasers have seen increasing use in the area of projection displays, which has driven production volumes in the industry, along with advancements in efficiency and cost.
Tomi Engdahl says:
SIL STRIKING POINT: Improved solid-state light sources will be key to the future of lighting
http://www.ledsmagazine.com/articles/2017/01/sil-striking-point-improved-solid-state-light-sources-will-be-key-to-the-future-of-lighting.html
Steele: What kind of performance is achieved with this approach?
Rudy: Wall plug efficiencies of up to 40% have recently been reported, up from 15% in 2005. Optical power outputs of 6W have also been reported. The main thing to realize here is that, unlike InGaN LEDs, these diode lasers do not suffer from “droop” (the roll-off of efficiency at higher drive currents).
Tomi Engdahl says:
SIL STRIKING POINT: Improved solid-state light sources will be key to the future of lighting
http://www.ledsmagazine.com/articles/2017/01/sil-striking-point-improved-solid-state-light-sources-will-be-key-to-the-future-of-lighting.html
Steele: How is a blue-emitting InGaN diode laser used to create white light?
Rudy: Just as in the case with using a blue LED as a pump source for creating white light, a phosphor is required. There are several options for pumping the phosphor, including transmissive (the white light emission is in the same direction as the pump beam) and reflective (the white light emission is at an angle relative to the pump beam). Also remote pumping, in which optical fiber is used to direct the laser light to the phosphor, is possible. This is the approach used by European automobile manufacturers to develop laser-based headlamps.
Tomi Engdahl says:
Laser Lighting Trial Starting in China
http://www.eetimes.com/document.asp?doc_id=1332182&
For perhaps the first time in the world, trials taking place in China next month will use lasers for street lighting, an innovation aimed at saving energy and eliminating the cost of expensive cabling infrastructure.
David Ho and the Jinjing Co. have developed the new lighting technology in the city of Fuzhou in China’s southeastern Fujian Province. Trials will start next month in the nearby city of Fuqing.
The technology uses laser beams of blue light to transmit energy across large distances without power lines. The beams strike devices that use quantum-induced materials to transform the laser energy into light for illumination.
While automakers such as Mercedes-Benz and BMW are already using a similar technology for car headlights, the trial in China is aimed at developing applications for street and highway lighting as well as environments not readily accessible to a power grid.
Researchers such as Steven DenBaars at UC Santa Barbara have been looking into the idea for several years. In theory, per square centimeter, a laser diode can produce 2,000 times as much light as an off-the-shelf LED. Lasers for conventional illumination are aimed at a phosphor that transforms blue laser light into more diffuse white light.
“Laser lighting will be a key solution for energy conservation in the future,” says Ho, who received his Ph.D in nuclear science. “This dream will soon become a reality.”
Laboratory tests of the technology in China indicate that it would save as much as two-thirds of the energy used in LED lighting, allowing the use of solar panels to provide power for the system. The use of laser beams to transmit power would also eliminate the need for power lines and the supporting physical infrastructure.