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Finally, a True Green Laser
dusty writes "Remember those green lasers from Star Wars? Turns out that faking green lasers has been easy for years, but making true green laser diodes has been the stuff of science fiction. Until recently, that is. Now researchers from Japan have created the world's first true green laser diode. Until now, only red and blue laser diodes were available, and now with the addition of green, new TVs and projectors that are more efficient can be produced. And if you were wondering how green lasers pointers are already produced, it is a hack that involved doubling the frequency of an infrared laser. The new true green laser diodes have much higher efficiency than the current 6%, leading many to expect big time laser display breakthroughs in the near future. Ars Technica has a well-written article on this breakthrough."
A laser diode is much more robust than a laser diode and the frequency-doubling package of nonlinear crystals.
No kidding!!! What do you say at this point?
I can't wait to get my new RGB Laser TV(TM)! Finally all those myths about how you'll go blind from staring at the TV will be reality!
This guy's the limit!
me to be the first to say: "laaayyser".
I'm sure Al Gore is thrilled with this news of green laser technology.
All we need now is some true frickin' sharks and we're in business.
Summation 2
Sweet. Now we just need it to draw on your eyeball.
And not blind you.
" Down inside the computer are three lasers - a red one, a green one, and
a blue one. They are powerful enough to make a bright light but not powerful
enough to burn through the back of your eyeball and broil your brain, fry
your frontals, lase your lobes. As everyone learned in elementary school,
these three colors of light can be combined, with different intensities, to
produce any color that Hiro's eye is capable of seeing.
In this way, a narrow beam of any color can be shot out of the innards
of the computer, up through that fisheye lens, in any direction. Through the
use of electronic mirrors inside the computer, this beam is made to sweep
back and forth across the lenses of Hiro's goggles, in much the same way as
the electron beam in a television paints the inner surface of the eponymous
Tube. The resulting image hangs in space in front of Hiro's view of Reality."
-- perl -e'print pack"H*","6e656d6f406d38792e6f7267"'
Firstly, I really don't see how the solid state lasers using frequency doubling are "fake" lasers.
Even so, outside the realm of small laser pointers, there are such a thing as gas lasers and they can produce a true green emission.
The possible breakthrough is the production of more efficient semiconductor lasers that emit in the green range, not the production of the first "True Green Laser".
Yeah, this is Slashdot...Whatever
Title should read "True green laser diode". 'Green' laser output has been achievable for for more than three decades with Argon ion, Krypton ion, and Copper vapor lasers. This just makes it more 'convenient' to achieve green output.
Sig this!
I am sure the guys building this laser would be more than a little pissed that you consider their laser 'fake' because it uses frequency doubling....
love is just extroverted narcissism
Blue > Green > Red
At this rate, the next generation games consoles will need a UV power light.
I'm way ahead of the curve.. the front of my computer has a frickin' gamma ray emitter as ITS power light.
This is a substitute for a clever sig that fits within the maximum number of characters.
If you were slowing down light to make it green you'd need to start with ultra-violet light, not infrared.
The real physics is well documented on Wikipedia. I recommend reading their page on non-linear optics.
Hate to break it to you. They were props.
The goggles do nothing!
Karnal
Oh, Edmund... can it be true? That I hold here, in my mortal hand, a nugget of purest Green?
I don't mind dating a girl that has been with everybody, as long as she had a good shower afterwards.
Let me c.
Hang on a minute, the article says light travels at the same speed in a vacuum. Stupid intarwebs. I'll fix Wikipedia and you can do all the others, OK?
Confucius say, "Find worm in apple - bad. Find half a worm - worse."
Nothing is slowed down. Light always goes at the same speed. Guess its name.
True in a vacuum, not true in practically anything else.
Finally! A year of moderation! Ready for 2019?
Goodbye DLP and LCD TVs and projectors.
Laser TVs:
- Have higher contrast ratios (talk about true black)
- Produce a range of colors broader than HDTV
- Use less energy
Unfortunately, they're still expensive. The only one that's available that I know of is the Mitsubishi Laservue. It's $7000 over at Amazon (http://www.amazon.com/dp/B001IAAD3K).
Hopefully, this green laser will make Laser TVs more of an (afforable) reality.
I void warranties.
That is not fully correct. It is true that the speed of light, in a vacuum, is a constant. But, the speed of light through a transparent medium is something less than c. How much light gets slowed down by a medium is frequency-dependent, as described by snell's law, which is how lenses are able to bend light.
The fact that the speed of light through a medium is less than c also allows for some more exotic phenomena, such as Cherenkov radiation, created when a particle's velocity through a medium exceeds that medium's speed of light (but definitely remains less than c).
From the article it says, "At Sumitomo Electric, they have overcome this problem by developing a GaN crystal which inhibits the efficiency drop, resulting in room temperature pulse operation of a laser diode emitting in the pure-green region at 531nm." Having worked on development of GaN blue lasers, there are a lot of challenges to getting a reliable, continuous wave (CW) diode laser that operates at this wavelength. My guess is they hammered their green diode laser with very short high power pulses just to get it to lase. So it is probably not a very useful laser if it cannot operate in CW mode.
They say the same thing, but they say it after the Canadian physicist.
SIG: HUP
*sigh* As usual, I'm way behind the times. I'm still using infrared, but I do plan to upgrade to the visible spectrum in the near future.
Slow down, cowboy! It has been 4 hours since you last posted. You must wait another few hours.
Could somebody elaborate a little bit more on this?
What is the issue with just using Indium to tune the band gap of GaN laser to the green and just having an InGaN laser?
Never mind, from the real paper,531 nm Green Lasing of InGaN Based Laser Diodes on Semi-Polar {2021} Free-Standing GaN Substrates, they were using InGaN
Lasing in pure green region around 520 nm of InGaN based laser diodes (LDs) on semi-polar {2021} free-standing GaN substrates was demonstrated under pulsed operation at room temperature. The longest lasing wavelength reached to 531 nm and typical threshold current density was 8.2 kA/cm2 for 520 nm LDs. Utilization of a novel {2021} plane enabled a fabrication of homogeneous InGaN quantum wells (QWs) even at high In composition, which is exhibited with narrower spectral widths of spontaneous emission from LDs than those on other planes. The high quality InGaN QWs on the {2021} plane advanced the realization of the green LDs. ©2009 The Japan Society of Applied Physics
Its very tempting to actually fork out the $$ and buy that one.
If someone is passing you on the right, you are an asshole for driving in the wrong lane.
I'm way ahead of the curve.. the front of my computer has a frickin' gamma ray emitter as ITS power light.
Hey, okay! We believe you. Just...try and calm down. Whatever you do, don't get angry.
(-1, Raw and Uncut is the only way to read)
I know you're joking, but some people won't realize that blu-ray (405nm) can store more data per disc than a green could. It can be focussed more tightly.
I had a sucky sig.
From the Slashdot summary: "And if you were wondering how green lasers pointers are already produced, it is a hack that involved doubling the frequency of an infrared laser. The new true green laser diodes..."
The intention is not to say they are fake lasers. The former green solid-state laser devices aren't just laser diodes; they are diodes plus another complicated structure. The new green laser devices are true diode lasers.
Corrections to the Ars article:
"Ever wonder why projector systems and televisions don't use laser illumination?"
More important error, and my guess about the correct information: "For instance, blue laser diodes use a gallium nitride system, and figuring out how to get indium nitride to mix through the gallium nitride evenly turned out to be quite difficult."
Full Text PDF of the Applied Physics Express scientific paper. (Free)
Laser projectors, dude!
Great contrast, tremendous color gamut, and they can project from any off angle since there's no real focusing issue.
Granted, there's more bugs to work out, but the lack of a cheap green laser was the probably the biggest issue holding the technology back.
How can I believe you when you tell me what I don't want to hear?
I don't like the use of public fields, please use a getter method.
Some languages have properties, or methods without parentheses: C#, for example.
It's a bug in the language.
Deleted
Now the trick is finding enough sharks to make the display useful.
We already have RGB + White lasers (consisting of multiple diodes), but I haven't seen anything useful done with them.
A prop on Firefly was named Vera.
You make my head explode every time you talk to me. And when your commenting, its like a lobotomy. You think that I am dumb, wont you just explain to me? I need a dictionary or car analogy.
Was I wrong to read that as if it was written by Gilbert & Sullivan?
[UID-HeinzIntel]
This is pretty awesome for the "toy" laser market too! Green lasers have always been pricey - I wanted to get a laser from Wicked Lasers but you can easily spend a few hundred dollars or more if you are tempted by the high powered ones. Better efficiency means its easier to make higher power, and no doped crystals means less concerns with complex alignment and cooling (the crystals get very hot!). I'd love to have a cheap high powered green laser!
In fact, here's a diagram of a typical green laser module with all the lenses and crystals aligned.
http://www.walshcomptech.com/repairfaq/sam/l54-101.gif
It's complex, to say the least!
-Taylor
Worldwide Military budgets: $2100 billion. Worldwide Space Exploration budgets: $38 billion. Really, world? Really?
would be to make a Green Lantern ring that uses green lasers controlled by Willpower. :)
Remember, Slashdot does not have a -1 disagree moderation, and no, troll, flamebait, and overrated are not substitutes.
According to my handy photonic spectrum wall chart, there are green lasers already: Argon ion, Copper vapor, Nd:YAG, Xe, and HeNe, as well as, of course, tunable dye lasers. Just not laser diodes, until now.
...the future crusty old bastards are already drinking the Kool-Aid.