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Researchers at Arizona State University have demonstrated the world's first white lasers:
The researchers have created a novel nanosheet – a thin layer of semiconductor [...] – with three parallel segments, each supporting laser action in one of three elementary colors. The device is capable of lasing in any visible color, completely tunable from red, green to blue, or any color in between. When the total field is collected, a white color emerges.
[...] The technological advance puts lasers one step closer to being a mainstream light source and potential replacement or alternative to light emitting diodes (LEDs). Lasers are brighter, more energy efficient, and can potentially provide more accurate and vivid colors for displays like computer screens and televisions. Ning's group has already shown that their structures could cover as much as 70 percent more colors than the current display industry standard.
Another important application could be in the future of visible light communication in which the same room lighting systems could be used for both illumination and communication. The technology under development is called Li-Fi for light-based wireless communication, as opposed to the more prevailing Wi-Fi using radio waves. Li-Fi could be more than 10 times faster than current Wi-Fi, and white laser Li-Fi could be 10 to 100 times faster than LED based Li-Fi currently still under development.
A monolithic white laser [abstract]
See also our story last year: Philips Launches "Intelligent LED Lighting" for Retail Stores.
(Score: 5, Informative) by TrumpetPower! on Saturday August 01 2015, @01:04AM
It's important to note that this is not true white light; it is, instead, a balanced mixture of three monochromatic light sources (of unspecified wavelengths).
There's great potential for some really nifty things related to human vision, especially for displays. But the light it emits is no different from the light you'd get from shining red, green, and blue laser pointers into the same diffuser. You get a lot of light of those exact wavelengths and absolutely no light of any other wavelength -- though, as with any other lighting technology, phosphors could help broaden the spectrum.
There's also a limit to how many colors you can reproduce with only three monochromatic primaries; see this article for details:
http://www.tftcentral.co.uk/articles/pointers_gamut.htm [tftcentral.co.uk]
The "sweet spot" would be 630nm, 527nm, and 467nm. Be interesting to know what the actual wavelengths of the lasers in question are....
Cheers,
b&
All but God can prove this sentence true.
(Score: 2) by TheLink on Saturday August 01 2015, @01:57AM
https://en.m.wikipedia.org/wiki/Color_rendering_index [wikipedia.org]
The thing about lighting is the light doesn't go straight to your eyes but reflects off stuff.So if the light has just three very skinny bands of r g b, something that is orange might appear red or dark red or even black if it only reflects a specific wavelength most of us see as orange.
(Score: 3, Interesting) by TheLink on Saturday August 01 2015, @02:04AM
(Score: 0) by Anonymous Coward on Tuesday August 04 2015, @02:17PM
More to the point, it cannot really generate all visible colours. Contrary to common belief, it is not possible to mix all colours from just three of them; indeed the sRGB colour space covers not even half of the full visible colour space. In particular, the spectral colours (those normally emitted by lasers) cannot be generated by mixing anything else.
The reason for this is that there are no three frequencies that each only trigger one of the three colour receptor types in our eye.