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Shark Technology

Researchers Demonstrate the World's First White Lasers 118

An anonymous reader writes: 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.
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Researchers Demonstrate the World's First White Lasers

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  • What? (Score:5, Funny)

    by Anonymous Coward on Wednesday July 29, 2015 @10:04PM (#50211367)

    It wasn't nanotubes, or 3D printed, or made by Elon Musk??? WTH!?

    • Yeah, plus it came from a "party school", not one of those elite left or right coast schools

      • With the lack of jobs for PhD's in academia (and elsewhere), ANY academic job gets tons of applicants. Only the best of the best get *any* job in academia nowadays.

        You can pretty much count on anyone in the US who has a faculty job being one of the best of the best. Furthermore, this person is going to have access to plenty of cheap PhD labor.

        Don't be surprised if you see pretty significant accomplishments coming from previously disregarded places.

        • Apparently you missed my inherent snarkiness, having attended said "party school" and encountered prejudiced behavior like the GP refers to.
          Not that anybody from Berkeley has ever behaved that way ;)

          • I attended that school (and department) also and can only count maybe 5 parties in as many years. As teachers would say, you get out of your education what you put into it.

            They had great equipment thanks to major facilities of Intel and Motorola being two miles away.

        • I considered the academic path, but rejected it as too high-risk. Instead I went into IT support, where I knew I could be confident of always finding employment - albeit at low pay.

          The plan worked: I'm now employed as an underpaid helpdesk-monkey, have had the same job for the best part of a decade, and could have it a decade still.

          • Dude, study up. I went the same path 15 years ago, right when the Dot Com crash happened. I studied my ass off, got a job doing the monkey thing, found cram schools to teach at, and as soon as I finished off my CCNP I've been employed ever since. I've got MCSEs in NT4, 2000, 2003, and Exchange, CCNA, CCNP R/S, CCNA security, working on CCIE written now (not a cheap test to study for, I'd have gotten it already, but spent years trying not to pay for study materials- the one month I've spent since ponying up

    • by idji ( 984038 )
      you forgot a new battery technology or graphite breakthrough!
    • It's all about lasers, but no mentioning of ze sharks. Highly disappointing...
  • 'White' light (Score:2, Interesting)

    by Kaenneth ( 82978 )

    Real full spectrum 'white' light, or just equalized peaks in the spectrum for RGB?

    • by Geoffrey.landis ( 926948 ) on Wednesday July 29, 2015 @10:16PM (#50211435) Homepage

      The summary is inaccurate, or at least confusing. The summary says "lasers that can shine light over the full spectrum of visible colors", but the article says that this is three monochromatic spikes, red, green, blue, which together appear white. It also says that the choice of colors is tunable... but tunable lasers aren't new.

      The summary also implies that it is "a" laser, but the article makes it clear that what they did is make three separate lasers on the same substrate (specifically "three parallel segments, each supporting laser action in one of three elementary colors.")

      • If the red, green and blue lasers can be 'tuned' for intensity then it can produce colors in the RGB colorspace, which is not necessarily the "full spectrum of visible colors"

        • For light, doesn't RGB cover the entire visible colorspace?

          • Re: (Score:3, Informative)

            by Khyber ( 864651 )

            Not necessarily. While these emitters are tunable, I doubt the red is getting down to 700nm, or the blue going into the 400-410nm violet range. Most RGB emitters, even tunable are peak 630nm red and 450-460nm blue. So this wouldn't cover the entire visible colorspace very accurately when it came to deeper reds and violets.

          • Not quite, but it's close enough to provide the illusion that it does. The discrepancy is easily seen by holding a picture of the blue sky up to the actual blue sky. In a side-by-side comparison you can see that the color is only approximate.

          • Not exactly. R, G, B are three points that form a triangle and using different combinations you can produce any color found in the triangle. However the total visible light available to humans is not shaped like a triangle, so no matter how well R, G, and B fit into the "corners" of human vision there are still other colors that they couldn't reproduce. Here's a chart that shows this: https://en.wikipedia.org/wiki/... [wikipedia.org]
            • by KGIII ( 973947 )

              Art class was so very very long ago, likely before you were a mote in your father's eye, actually. I never took any of the arts classes in college - I did take creative writing and music classes which served to fill my prerequisites. Anyhow, I may be wrong. Isn't black the presence of all colors and white the absence of any color?

              I could see using the RGB to create black but how does one manage to get a true white? It seems (I did not even do more than skim the summary) that there would need to be some filt

      • by guises ( 2423402 )
        They're also not LASERs (Light Amplification by Stimulated Emission of Radiation), but are rather laser diodes. Am I being too picky when I notice that? Electrical engineers tend to get annoyed when I point out that their version of lasers aren't real lasers.
        • Am I being too picky when I notice that?

          Yeah. [wikipedia.org]

          • by guises ( 2423402 )
            I'm not following your point. You have linked to a wiki article discussing one component of a laser. Does that... no, I just don't get it.
            • by Khyber ( 864651 )

              "Examples of active laser media include:

              Semiconductors, e.g. gallium arsenide (GaAs), indium gallium arsenide (InGaAs), or gallium nitride (GaN).[4]"

              So yes, semiconductors, AKA LEDs, ARE usable for a lasing medium.

              So yes, it IS a LASER.

        • Yes, you are. The you are right to say that the origin of the name comes from a method to produce light with those specific characteristic. But very few to non device still use this method today.

          Gas cavity laser, laser diodes, chemical laser, etc. all do not pass in your restricted vision of what a laser ist. But long has been established to call laser a device that creates light with coherent characteristics as did the first early LASERs.

          In your world, it would be wrong to call a car a car because there a

          • by KGIII ( 973947 )

            I still get a wee bit finicky about the word "MODEM" being thrown about. The is no cable modem nor DSL modem. In both cases the signal remains digital. MODEM is MOdulation and DEModulation. Whilst trivial it still irks me a little tiny bit but not enough to actually comment on it most of the time. That and, well, the options are a bit clunky to type or to say. Still, I prefer to use the word router, I suppose.

            • by geogob ( 569250 )

              I do not know for DSL devices, but DOCSIS cable "modem" really are modem. The modulate/demodulate various flavours of QAM, depending on the version.

              • by KGIII ( 973947 )

                How true. I had forgotten about those. Thanks - statement corrected in my head. ;)

        • Yes, laser process is happening in laser diodes. The electrical engineers are annoyed at your astounding ignorance of the subject

      • While this first proof of concept is important, significant obstacles remain to make such white lasers applicable for real-life lighting or display applications. One of crucial next steps is to achieve the similar white lasers under the drive of a battery. For the present demonstration, the researchers had to use a laser light to pump electrons to emit light. This experimental effort demonstrates the key first material requirement and will lay the groundwork for the eventual white lasers under electrical operation.

        The thing they made is probably best thought of as nano-interleaved resonator cavity for a laser diode (which needs to have certain band gaps to emit the light). Apparently for this proof of concept, they actually had to excite this nano-structured cavity, with an actual laser. These nano-structures couples the energy to desired tunable optical wavelengths which are nano-interleaved and thus allows emission of "white" light from the laser diode structure.

        As far as I can tell, the breakthrough is to manufa

    • by Khyber ( 864651 )

      EQ Peaks. Three tunable emitter crystals on the same substrate.

  • Isn't the point of a laser that it's a single wavelength? Doesn't this fly in the face of that or am I missing something?
    • by Khyber ( 864651 )

      This is a tunable multi-wavelength laser with tunable red, green, and blue emitters. This makes it useful for scanning various things with different wavelengths at the same time so you may get multiple measurements at once. Good for protein fluorescence and stuff.

    • by Temkin ( 112574 )

      Isn't the point of a laser that it's a single wavelength? Doesn't this fly in the face of that or am I missing something?

      Coherence & single wave length. A laser has all the waves in lock step.

      • It's never really a single wavelength, just a frequency with (originally) a very narrow bandwidth. Very large-bandwidth lasers were developed about 30 years ago, and few-wavelength pulses made using truly white light have been available for nearly 20 years. These are still incredibly useful, as their coherence times are huge, and with the appropriate phase profile over their spectrum they can make near-arbitrary waveforms on a femtosecond-picosecond timescale. The big benefit with this is the miniaturizatio
    • by dywolf ( 2673597 )

      no the point of a laser is that the actual light waves are coherent.
      the single wavelength is more of a byproduct of the process, albeit a very useful one.

      • by fisted ( 2295862 )

        ....what? there is no way for 'the actual light waves to be coherent' than to have them be of a single wavelength.

  • White! (Score:5, Funny)

    by digsbo ( 1292334 ) on Wednesday July 29, 2015 @10:09PM (#50211383)
    These lasers are oppressing other lasers! They need to check their privilege!
  • WRONG (Score:5, Informative)

    by Khyber ( 864651 ) <techkitsune@gmail.com> on Wednesday July 29, 2015 @10:10PM (#50211387) Homepage Journal

    This is not the first WLL. Those have been available for at least half a decade.

    This is the first SOLID STATE WLL.

    What's unique is that they figured out a way to grow three different crystals next to each other on the same substrate without having fatal flaws.

    Holy fuck can the editors even be bothered to fact-check?

    Oh, yea, what editors?

  • Not white (Score:5, Informative)

    by Anonymous Coward on Wednesday July 29, 2015 @10:11PM (#50211399)

    So it's not white, it's tri-colour.

  • by SuperKendall ( 25149 ) on Wednesday July 29, 2015 @10:11PM (#50211403)

    A racist laser, literally white power.

  • by p0p0 ( 1841106 )
    Someone get the sharks. This is as good as it gets.
  • by Michael Woodhams ( 112247 ) on Wednesday July 29, 2015 @11:53PM (#50211833) Journal

    If you've ever played with a normal monochrome laser in a dark room, you'll have seen how laser illumination makes things look speckly. Illuminating with this "white" laser will make superimposed speckly in three colours, with the locations of the speckles not coinciding, so it would be iridescent speckly.

    • I have noticed the speckly too, but could not work out the mechanism behind it.

      • by Anonymous Coward

        You're seeing an interference pattern. [wikipedia.org]

        with the locations of the speckles not coinciding, so it would be iridescent speckly.

        It might also act as speckle contrast reduction through wavelength diversity. Although chances are the wavelengths differ by too large an amount.

    • by Misagon ( 1135 )

      So that means that up close, an image projected with these laser devices would look somewhat like a Pointilism [wikipedia.org] painting?
      I am not sure that I would disapprove, actually.

      • Not just a projected image, but anything it illuminates (so long as there is little other illumination to mess up the effect.)

  • And... (Score:4, Funny)

    by WSOGMM ( 1460481 ) on Thursday July 30, 2015 @04:12AM (#50212515)
    in other related news, researchers tightly focus light bulb light. They contend that their invention should have a wide spectrum of uses, but critics argue that their results aren't coherent.
  • It was discussed since yesterday over on Reddit and the authors of the original paper even arrived to provide clarifications. That's how bad this article linked here is.
    See the reddit discussion here:
    https://www.reddit.com/r/scien... [reddit.com]

  • "What?!?! No! No one EVER made them like this!!"

  • Great White Lasers! Finally they're getting them on the sharks!

  • It is a discrete laser that can emit three distinct wavelengths.

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