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
So we’re talking a laser with “privilege”. Hopefully it LEARNS ITS LESSON.
OK that makes sense.
Kinda like Fission, we still have to put more energy in than we can get out?
It will be passed over for use over all other color lasers, intentionally weakened, cost more, and finally used when it proves to be good at being what it does.
Sorry to be a pest, but the only Laser I’ve ever been in contact with is the one I use to torture the cats.
So, theoretically, if you wanted to take out a target at 60 yards, and then at 100 yards you would have to change the focus of the laser?
I see that my thought that this might be a reality one day seems to be misplaced. They evidently don’t work anything like I thought they did.
That.
In a vacuum coherent light would travel for ever. So a 1 second laser burst would be like a cylinder of light travel thru space and time forever. So range isn't really a problem. You can bounce lasers off of lunar reflectors put there by Apollo astronauts. The focus only concentrates the energy.
Well, within the tolerance of the phase lock. If that wasn't literally perfect, or somehow constantly realigned by a phase alignment field traveling with it, the coherent waves would eventually separate into a disbursed, spreading vector pattern and just... dissipate. That's the flaw in the SciFi idea of sending information across space with lasers - space is really, REALLY big, and provides plenty of distance for a nice tight beam to turn into a suffused, random, dim, meaningless glow.
A lot more than a walk to the chemist, that’s peanuts compared to space.
My interest in lasers is in cutting and welding non metallic materials. A non fixed movable beam and cost are the problems. A handheld movable beam, low cost laser with operator controlled temperatures of 1200 degrees Celsius to 2600+ degrees Celsius is what I want.
As long as you can use a nice fat powercord to a wall socket, your desire seems not only feasible, but quite do-able.
Of course there may be some safety-issues that arise with a hand-held death ray, even one with a power cord. Wouldn’t want to cut the house in half while reaching for a phone call...
I assume there is no black laser, so this is racist and based on white privilege.
“I see your laser is more privileged than mine.”
The “daser” will get affirmative action privilege as soon as it is invented.
Get an unlicensed nuclear accelerator stuffed into a backpack and the power problem is solved. Also don’t cross the streams with another similar powered unit. Crossing the streams is bad.
The “Lasers of Color” will hate the white laser and blame it for all their problems.
That thing would poke holes in an aircraft!
You mean fusion, but yes.
No, if you could find a dense enough power source it would be possible.
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.
Though I’m not really sure a laser would be the way to go personally. I think with that kind of energy source available you’re better off with a railgun.
Sorry, I started to put fusion, and cold fusion popped into my head.
Fusion is slamming the atoms together, right, and fission is separating 1 into to 2 different atoms?
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