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The First White Laser
IEEE Spectrum ^ | 27 Jul 2015 | Charles Q. Choi

Posted on 07/29/2015 3:54:30 PM PDT by Talisker

Scientists and engineers at Arizona State University, in Tempe, have created the first lasers that can shine light over the full spectrum of visible colors. The device’s inventors suggest the laser could find use in video displays, solid-state lighting, and a laser-based version of Wi-Fi.

Although previous research has created red, blue, green and other lasers, each of these lasers usually only emitted one color of light. Creating a monolithic structure capable of emitting red, green, and blue all at once has proven difficult because it requires combining very different semiconductors. Growing such mismatched crystals right next to each other often results in fatal defects throughout each of these materials.

But now scientists say they’ve overcome that problem. The heart of the new device is a sheet only nanometers thick made of a semiconducting alloy of zinc, cadmium, sulfur, and selenium. The sheet is divided into different segments. When excited with a pulse of light, the segments rich in cadmium and selenium gave off red light; those rich in cadmium and sulfur emitted green light; and those rich in zinc and sulfur glowed blue.

The researchers grew this alloy in stages, carefully varying the temperature and other growth conditions over time. By controlling the interplay between the vapor, liquid, and solid phases of the different materials that made up this nano-sheet, they ensured that these different crystals could coexist.

The scientists can individually target each segment of the nano-sheet with a light pulse. Varying the power of the light pulses that each section received tuned how intensely they shone, allowing the laser to produce 70 percent more perceptible colors than the most commonly used light sources.

Lasers could be far more energy-efficient than LEDs: While LED-based lighting produces up to about 150 lumens per watt of electricity, lasers could produce more than 400 lumens per watt, says Cun-Zheng Ning, a physicist and electrical engineer at Arizona State University at Tempe who worked on the laser. In addition, he says that white lasers could also lead to video displays with more vivid colors and higher contrast than conventional displays.

Another important potential application could be "Li-Fi", the use of light to connect devices to the Internet. Li-Fi could be 10 times faster than today’s Wi-Fi, but "the Li-Fi currently under development is based on LEDs," Ning says. He suggests white-laser based Li-Fi could be 10 to 100 times faster than LED-based Li-Fi, because the lasers can encode data much faster than white LEDs.

In the future, the scientists plan to explore whether they can excite these lasers with electricity instead of with light pulses. They detailed their findings online 27 July in the journal Nature Nanotechnology


TOPICS: Technical
KEYWORDS: laserprivilege; lasersberayciss; racistlasers; stringtheory
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To: GeronL

Or a missile.


41 posted on 07/29/2015 6:14:52 PM PDT by MHGinTN (Is it really all relative, Mister Einstein?)
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To: drbuzzard

10-4 Got it.
Thank you.
Also for the next question I sent.
I appreciate your patience, and knowledge.


42 posted on 07/29/2015 6:16:04 PM PDT by rikkir (You can lead a horde to knowledge but you canÂ’t make them think. (TnkU Ctdonath))
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To: Talisker
I want a laser that makes PEW! PEW! PEW! noises.
43 posted on 07/29/2015 6:46:07 PM PDT by uglybiker (nuh-nuh-nuh-nuh-nuh-nuh-nuh-nuh-nuh-nuh-nuh-nuh-nuh-nuh-nuh-nuh-BATMAN!)
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To: uglybiker
I want a laser that makes PEW! PEW! PEW! noises.

How to make the laser blaster sound from Star Wars

44 posted on 07/29/2015 7:05:01 PM PDT by Talisker (One who commands, must obey.)
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To: drbuzzard
I rather suspect batteries will never cut it, but something like a high temperature superconductor ring looping a lot of current which can be siphoned off using induction could make this happen.

Been done.


45 posted on 07/29/2015 7:11:22 PM PDT by Talisker (One who commands, must obey.)
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To: GeronL

Same here, you beat me to it (being racist). Well, somewhere, the noted New Black Panther Scientist, Shamballa L. Shabazz is working on the “Black Laser” that sucks out all light in a 100 yard radius. Reminds me of the old “Black Ray Gun” in the old TSR role playing game, “Gamma World,” where if a living being gets hit wit it, instant death.


46 posted on 07/29/2015 8:02:48 PM PDT by Nowhere Man ("I wish we were back in the world of Andy Williams." - My mother, 1938-2013, RIP)
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To: rikkir

Well, laser take a lot of power. I have an online friend who, back in the 1980s, made a combo “laser/taser” where the laser would ionize the air and the electricity would travel down the path. He zapped groundhogs unconscious with it and you only had a few shots when powered by a car battery. Unless you want to lug around a half dozen car batteries, portable lasers are a long way away.


47 posted on 07/29/2015 8:07:10 PM PDT by Nowhere Man ("I wish we were back in the world of Andy Williams." - My mother, 1938-2013, RIP)
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To: Nowhere Man

I have an online friend who, back in the 1980s, made a combo “laser/taser” where the laser would ionize the air and the electricity would travel down the path.

That’s very cool. I hope he’s still working on it.
Somebody mentioned “Looping Semi-Conductors” and “High Volume Fast Charging Capacitors” earlier. It might solve his problem.


48 posted on 07/29/2015 8:19:14 PM PDT by rikkir (You can lead a horde to knowledge but you canÂ’t make them think. (TnkU ctdonath2))
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To: Talisker

Do you know of any existing laser like that?


49 posted on 07/30/2015 7:34:31 AM PDT by free_life (If you ask Jesus to forgive you and to save you, He will.)
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To: free_life
Do you know of any existing laser like that?

None that I can confirm or deny.

50 posted on 07/30/2015 10:10:46 AM PDT by Talisker (One who commands, must obey.)
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