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South African Research Team Creates World's First Digital Laser

samzenpus posted about 7 months ago | from the better-focus dept.

Shark 81

smi.james.th writes in with news about new laser technology developed in South Africa. "The Council for Scientific and Industrial Research (CSIR) announced in Pretoria on Tuesday that it had developed the world's first digital laser. 'I am always very cautious about using the term "breakthrough",' noted Science and Technology Minister Derek Hanekom. 'We scrutinized this very carefully before we said that this is really new! South African scientists are once again making noteworthy contributions to the world.'... A normal laser contains two mirrors, opposed to each other and at opposite ends of the instrument. One is highly reflective and the other is a curved, partially reflective mirror. In the digital laser, the curved mirror is replaced by a liquid crystal display (LCD) system. The LCD is connected to a computer and monitor."

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81 comments

Important part the summary neglected (5, Informative)

mcgrew (92797) | about 7 months ago | (#44889061)

Researchers use the computer to specify the laser beam shape they require and to programme it into the LCD. By this means, one laser can swiftly produce many different beam shapes. Previously, changing the shape of a laser beam required physically replacing the curved mirror in the laser. As the mirror has to be carefully aligned, this is a time consuming process.

Re:Important part the summary neglected (2)

mcgrew (92797) | about 7 months ago | (#44889085)

Oops, I forgot the blockquotes. That was from TFA (not a good FA IMO)

Re:Important part the summary neglected (3, Informative)

hedwards (940851) | about 7 months ago | (#44889139)

I fail to see how that's digital, but it's a cool advancement none the less. The beam itself is still just a laser beam.

Re:Important part the summary neglected (3, Funny)

TechyImmigrant (175943) | about 7 months ago | (#44889479)

Maybe it has fingers.

Re:Important part the summary neglected (0)

The Grim Reefer (1162755) | about 7 months ago | (#44889543)

Maybe it has fingers.

I believe that would be "a finger". It's digital after all. It's either flipping you the bird, or it's not. If it had fingers, it would be analog. ;-)

Re:Important part the summary neglected (0, Troll)

Anonymous Coward | about 7 months ago | (#44890155)

Wow, hate to be lame-joke-explainer:

Digit is latin for finger.

And you're an idiot.

No, it's not latin for "you're an idiot", you are just an idiot.

Re:Important part the summary neglected (0)

Anonymous Coward | about 7 months ago | (#44891133)

No need to start calling others idiots, just because they don't get a latin joke. He wasn't hostile, why are you?

Re:Important part the summary neglected (1)

Anonymous Coward | about 7 months ago | (#44891585)

If it had all the fingers, it would be manual, not digital.

Re:Important part the summary neglected (3, Insightful)

mcgrew (92797) | about 7 months ago | (#44890415)

I fail to see how that's digital

An English major wrote it. It uses a computer-controlled LCD instead of a curved mirror. There are benefits, TFA isn't very good at explaining them because the guy who wrote the article either didn't understand the concepts or really sucks at communicating them. You really have to look hard through the overabundance of redundant marketspeak verbiage to grok it.

Re:Important part the summary neglected (3, Insightful)

Em Adespoton (792954) | about 7 months ago | (#44890927)

I fail to see how that's digital

An English major wrote it. It uses a computer-controlled LCD instead of a curved mirror. There are benefits, TFA isn't very good at explaining them because the guy who wrote the article either didn't understand the concepts or really sucks at communicating them. You really have to look hard through the overabundance of redundant marketspeak verbiage to grok it.

I doubt an English major wrote it -- it looks an awful lot like a Communications major wrote it; an English major wouldn't use an overabundance of redundant marketspeak, but would instead make all sorts of obscure references in fairly terse but accurate English.

Re:Important part the summary neglected (0)

Anonymous Coward | about 7 months ago | (#44891435)

I doubt an English major wrote it

Mebbe a journo wrote it, and not any rank of soldier?

Re:Important part the summary neglected (1)

jones_supa (887896) | about 7 months ago | (#44891553)

I fail to see how that's digital, but it's a cool advancement none the less. The beam itself is still just a laser beam.

There's a lot of misuse of the word "digital". It ultimately just means something which comes in quantified pieces. Not necessarily even electronic or computerized. It is a cool word for marketing though...

Re:Important part the summary neglected (0)

Anonymous Coward | about 7 months ago | (#44892099)

It's a huge advancement in Cat Toy Technology! lmao

Re:Important part the summary neglected (1)

khundeck (265426) | about 7 months ago | (#44892511)

I fail to see how that's digital ...

Well you said it not me. :-) ["fail"] It's pretty obvious FTA. Maybe you're subtly suggesting that lasers have always been digital??? I don't know enough about it.

FTA: A 'laser beam' apparently has a few components. The "analogue" way - two mirrors on each end of the device. The "digital" way - replace the one curved mirror with an LCD THAT HOOKS UP TO A COMPUTER. The computer controls the LCD (orientation of the liquid crystals) and ultimately affects the laser shape. I'm amazed that they can use an LCD instead of the mirror..

KPH

PS: FRIGGIN' DIGITAL LAZZZZZERS!?!?!!

Re:Important part the summary neglected (1)

hedwards (940851) | about 7 months ago | (#44893417)

My parents can hook their record player up to a computer, does that mean that the record player is digital?

The fact is that the laser is just a laser, they've added some cool technology to it, but it's still the same laser that it always was. Using digital controls doesn't make for a digital laser, there've been digital controls for years.

Re:Important part the summary neglected (0)

Anonymous Coward | about 7 months ago | (#44894191)

My parents can hook their record player up to a computer, does that mean that the record player is digital? The fact is that the laser is just a laser, they've added some cool technology to it, but it's still the same laser that it always was. Using digital controls doesn't make for a digital laser, there've been digital controls for years.

When I listen to music the sound comes out of an analog speaker. Does that mean a CD is analog? Same thing here. Of course the laser isn't digital, digital is an abstraction and doesn't exist in the real world. It only exists in Plato's immaterial universe of forms.

Re:Important part the summary neglected (1)

hedwards (940851) | about 7 months ago | (#44896035)

The point I was making is that this is still the same laser as ever, the fact that they've added nifty controls to it, doesn't change the fact that it's still the same laser as before. They've just added more options and increased the flexibility.

Re:Important part the summary neglected (0, Funny)

Anonymous Coward | about 7 months ago | (#44889171)

Nonsense, /.summaries are the epitome of good journalism. Another glorious day on slashdot! A day on slashdot is like a day on the farm. Every meal's a banquet! Every paycheck a fortune! Man, I love slashdot!

Re:Important part the summary neglected (4, Interesting)

girlintraining (1395911) | about 7 months ago | (#44889185)

As the mirror has to be carefully aligned, this is a time consuming process.

This has already been partially solved using nano mirrors -- basically the rear reflector is a pile of mirrors that each have independent servos. It's nano tech. Like I said... early stages.

Re:Important part the summary neglected (4, Funny)

ackthpt (218170) | about 7 months ago | (#44889279)

Researchers use the computer to specify the laser beam shape they require and to programme it into the LCD. By this means, one laser can swiftly produce many different beam shapes. Previously, changing the shape of a laser beam required physically replacing the curved mirror in the laser. As the mirror has to be carefully aligned, this is a time consuming process.

This will be of immense benefit to mankind.

Once I fit one of these in the back of my car it will spell out messages for drivers following me to read; e.g. Your Turn Signal Has Been On For The Past 3 Miles.

Re:Important part the summary neglected (2)

PopeRatzo (965947) | about 7 months ago | (#44889791)

Once I fit one of these in the back of my car it will spell out messages for drivers following me to read; e.g. Your Turn Signal Has Been On For The Past 3 Miles.

"Spell out messages"? Hell, I want one that will vaporize the guy that's been tailgating me since the St Louis turnoff.

Re: Important part the summary neglected (0)

Anonymous Coward | about 7 months ago | (#44890297)

They probably wouldn't be tailgating you if you would get out of the left lane...since that's the passing lane...

Re: Important part the summary neglected (1)

PopeRatzo (965947) | about 7 months ago | (#44890323)

get out of the left lane...since that's the passing lane...

Since when? I thought I'm supposed to drive over there when I've had more than 3 drinks.

And less than 5, of course. I'm not a drunk or anything.

Re: Important part the summary neglected (0)

Anonymous Coward | about 7 months ago | (#44892667)

The left lane IS the slow lane you insensitive clod! =P
[I live in a Left-hand drive country]

Re:Important part the summary neglected (1)

mcgrew (92797) | about 7 months ago | (#44890437)

Their lasers aren't that powerful yet and anyway, they only do infrared so far so good luck reading the messages.

Re:Important part the summary neglected (1)

Em Adespoton (792954) | about 7 months ago | (#44890937)

Researchers use the computer to specify the laser beam shape they require and to programme it into the LCD. By this means, one laser can swiftly produce many different beam shapes. Previously, changing the shape of a laser beam required physically replacing the curved mirror in the laser. As the mirror has to be carefully aligned, this is a time consuming process.

This will be of immense benefit to mankind.

Once I fit one of these in the back of my car it will spell out messages for drivers following me to read; e.g. Your Turn Signal Has Been On For The Past 3 Miles.

And here I thought you were going to say "Once I fit one of these on the back of my shark...."

Summary seems to be somewhat misleading. (4, Informative)

Ungrounded Lightning (62228) | about 7 months ago | (#44889329)

My impression is that, because the mirror is "replaced" with the LCD, the LCD is inside the cavity, with each pixel modulating either the Q or the polarization of a particular chunk of the cross-section of the cavity. This amounts to adjusting the gain of the various modes of the cavity and thus switching which one(s) oscillate and consume the energy from the amplifier in the cavity.

Though the modes that are selected would not be mapped one-to-one onto the pixels, , you can control a lot of modes with the ciquid crystal display - probably all of them available, or up to the number of pixels in the liquid crystal device.

You can also switch them as fast as the liquid crystal switches. With modern drivers (which remember the previous state of the liquid crystal in each pixel and temporarily overdrive those that must change more in order to switch them rapidly, rather than just letting them settle passively into the new state) you can switch it at 60 Hz or better.

You might use holographic techniques to change the angle of the beam, or emit a number of beams of various intensities in various directions. Result: Scanning and image formation without moving parts (other than the molecules in the display).

I think the computation to turn it into a (one-color) projector would be pretty much a straight 2-D FFT times a nonliinear tweak to deal with energy-stealing among modes.

I'd like to see versions of this with array-of-Kerr-cells in place of the liquid crystal device (for more rapid modulation, at the cost of high voltage drivers), or digital light processors for the mirrors (though the latter are more on/off than continuously adjustable so they might be more limited on what beams they can form).

Re: Summary seems to be somewhat misleading. (0)

Anonymous Coward | about 7 months ago | (#44889471)

This is over my head.

How many football fields that?

Re: Summary seems to be somewhat misleading. (2)

Lumpy (12016) | about 7 months ago | (#44889621)

About 6, but only if you dont have quantum entanglement.

Re: Summary seems to be somewhat misleading. (0)

Anonymous Coward | about 7 months ago | (#44889659)

This is over my head.

How many football fields that?

Twice as many as will fit in a double decker bus.

Re: Summary seems to be somewhat misleading. (0)

Anonymous Coward | about 7 months ago | (#44890141)

One -- the size of Rhode Island.

Re:Summary seems to be somewhat misleading. (1)

Sarten-X (1102295) | about 7 months ago | (#44889523)

I think the computation to turn it into a (one-color) projector would be pretty much a straight 2-D FFT times a nonliinear tweak to deal with energy-stealing among modes.

And that means a full-color high-quality laser projector is just over 3x as expensive, but still feasible. I, for one, am excited.

Re:Summary seems to be somewhat misleading. (1)

mcgrew (92797) | about 7 months ago | (#44890485)

Don't get too excited yet, so far it can only do infrared. What surprised me was that pixel density on LCDs was so good. We could have digital holograms right now using good old fashioned 1970s mirrored lasers in the displays.

I don't know why nobody's done it.

Re:Summary seems to be somewhat misleading. (1)

camperdave (969942) | about 7 months ago | (#44889741)

To run "holographic" displays, don't you need to be able to control the liquid crystal shutter down to at least the wavelength of the light being controlled? After all, a hologram is merely an interference pattern, and the interference pattern would be on that scale. I may be out of the loop, but I don't think we have nano-scale liquid crystal tech yet.

Re:Summary seems to be somewhat misleading. (1)

Ungrounded Lightning (62228) | about 7 months ago | (#44895901)

Not at all. The size (spacing) of the pixels relative to the wavelength limits the angle through which you can (first-order) diffract the beam,

A hologram of a scene where only a small region, very near the spot the reference beam is aimed at, i.e. one that leaves most of the light nearly parallel to the reference beam on reconstruction, is a very low-resolution, big-blobby thing.

Re:Summary seems to be somewhat misleading. (1)

goombah99 (560566) | about 7 months ago | (#44890029)

I'd like to see versions of this with array-of-Kerr-cells in place of the liquid crystal device (for more rapid modulation, at the cost of high voltage drivers), or digital light processors for the mirrors (though the latter are more on/off than continuously adjustable so they might be more limited on what beams they can form).

your wish is my command:
http://www.ncbi.nlm.nih.gov/pubmed/18319825 [nih.gov]

Re:Summary seems to be somewhat misleading. (0)

Anonymous Coward | about 7 months ago | (#44891079)

I was thinking of being able to beam images/video directly into the pupils (low enough energy not to harm your eyes).

Re:Summary seems to be somewhat misleading. (1)

thygate (1590197) | about 7 months ago | (#44891305)

60 Hz would be terrible. Let's imagine they can IQ modulate 64 symbols (6 bits per symbol) with a samplerate of 60 Hz, that gets you 6 * 30 (Nyquist) = 180 bits per second.

Re:Summary seems to be somewhat misleading. (1)

Ungrounded Lightning (62228) | about 7 months ago | (#44895827)

60 Hz would be terrible. Let's imagine they can IQ modulate 64 symbols (6 bits per symbol) with a samplerate of 60 Hz, that gets you 6 * 30 (Nyquist) = 180 bits per second.

That's per pixel in the modulator. Now multiply by the number of (mega) pixels.

The modulator is essentially the guts of an LCD display so you get the same bandwidth as the video image it could display. What's new is:
  - You're modulating the(many) modes of the cavity itself, rather than shaping the beam after it emerges.
  - You're modulating the modes rapidly, rather than by hand-replacing components (call it one symbol per hour if you're good at it).

Re:Important part the summary neglected (1)

Osgeld (1900440) | about 7 months ago | (#44889431)

Thank you, note to slashdot, you could replace the 2nd and 3rd sentence in your pretty much worthless summary with the ones provided above and turned it into something that had a fucking point.

Re:Important part the summary neglected (1)

citizenr (871508) | about 7 months ago | (#44889581)

Previously, changing the shape of a laser beam required physically replacing the curved mirror in the laser. As the mirror has to be carefully aligned, this is a time consuming process.

But picking crystal for your lightsabe^^^laser is a rite of passage!

Re:Important part the summary neglected (1)

msauve (701917) | about 7 months ago | (#44889635)

Thanks for that. This seems to be a "digital LASER" only in relation to a very specific quality. It is certainly not the "world's first digital LASER." There are millions of LASERs which operate digitally already in common use - many (most?) Ethernet fiber optic transceivers use LASERs which are digitally modulated.

(much 1000base is LASER, AFAIK all 10Gbase is LASER)

Too bad this idea was patented in 2000 (2)

goombah99 (560566) | about 7 months ago | (#44890001)

here's the patent from 2000
https://docs.google.com/viewer?url=patentimages.storage.googleapis.com/pdfs/US6031852.pdf [google.com]

instead of an LCD, which are slow, the inventors used an accoustoptic modulator as the pattern former. Those are fast. In fact they are so fast they could also use the pattern former to sweep the wavelength in real time or q switch the laser.

Re:Important part the summary neglected (2)

LoRdTAW (99712) | about 7 months ago | (#44893959)

I would assume YMMV but the rear mirrors in industrial lasers are quite easy to tune. I work at a laser welding shop where we use lamp pumped pulsed Nd:YAG lasers. Rear mirror alignment is done manually using two screws and takes about 20-30 minutes thanks to the built in tuning meter. You set a pulse rate and width (eg 20Hz, each pulse 2ms long) and watch the power meter. You start with a number that gives you 10 watts and then tune until you can't get the power any higher(you now might have 15W. Then you do 50W, 100W ,150W etc. until you hit the lasers power limit (500W for our machines) and your done. I did this twice when we configure a workstation and added a new laser. This is for our three Lumonics JK lasers. The ancient Raytheon is a bit different and is tuned by a service tech and the Trumpf we have is rock solid and never touched though has the worlds most shitty configuration software.

Re:Important part the summary neglected (0)

Anonymous Coward | about 7 months ago | (#44894905)

Depends on what you are using the laser for and what wavelength it is. A solidly built, industrial Nd:YAG laser would be on the easier end. If you are using a Nd:YAG in a research situation where you are pushing the power to the limits of your equipment, several issues pop up (e.g. ASE) that can be dealt with by careful tuning. Something like mode locking lasers can be a lot messier, although I only have second hand experience for that via the cursing of coworkers. Something like discussed in the article could be useful for when trying to pick out or switch between different modes in a single oscillator, which would probably take a lot more tuning that just keeping a system tuned up.

Re:Important part the summary neglected (0)

Anonymous Coward | about 7 months ago | (#44896177)

Or you could just screw on one of those little brass things to the end of the laser pointer... I have one that makes stars and circles.

Half as effective (4, Funny)

Anonymous Coward | about 7 months ago | (#44889111)

Unfortunately it's half as effective.

See, the 1s have sharp edges and really abrade the material, but the 0s just roll right off.

Re:Half as effective (0)

Anonymous Coward | about 7 months ago | (#44889227)

Unfortunately it's half as effective.

See, the 1s have sharp edges and really abrade the material, but the 0s just roll right off.

Once you strap it on the back of a shark, none of that matters.

Re:Half as effective (0)

Anonymous Coward | about 7 months ago | (#44890469)

Good point! "Criminal activities." What are your *criminal activities*? Because that's why you're here! You've got your own criminal activities that you want to hide. That's all you're here for, to HIDE your OWN crimes.

Re:Half as effective (0)

Anonymous Coward | about 7 months ago | (#44893869)

Yes but in the right circumstances the increased mass of the 0s helps to smash things down. More general purpose but less useful. Perhaps they'll come out with one that has a 0/1 switch?

All we need now (3, Funny)

Anonymous Coward | about 7 months ago | (#44889129)

Is digital sharks

Patent troll (1)

tepples (727027) | about 7 months ago | (#44889239)

I was under the impression that nonpracticing entities specializing in asserting broad patents of questionable quality had the "sharks" part covered.

Monster Cables (0)

Anonymous Coward | about 7 months ago | (#44889363)

Cant wait for the Digital Laser Gold Platinum Extreme $500 HDMI cables!

Re:Monster Cables (1)

Behrooz Amoozad (2831361) | about 7 months ago | (#44889557)

Re:Monster Cables (0)

Anonymous Coward | about 7 months ago | (#44890019)

The reviews on that are genuinely hilarious.

Re:Monster Cables (0)

Anonymous Coward | about 7 months ago | (#44890027)

Especially the one from George Takei "The minute I plugged this cable in, I knew something was amiss. The first evidence? The small wormhole that appeared in our living room, right next to our holstein cowhide recliner...."

Yeah, but is it 3D printed? (0)

Anonymous Coward | about 7 months ago | (#44889389)

Maybe in space, privately?

Rather long in the tooth? (1)

leftover (210560) | about 7 months ago | (#44889925)

Spatial light modulators to shape laser beams were big stuff 25 years ago but I haven't seen mention of them for a very long time. Is there really anything new in this work or is it something (nearly) forgotten being rediscovered?

Re:Rather long in the tooth? (0)

Anonymous Coward | about 7 months ago | (#44892477)

I built similar for UCSD chem department about 20 years ago.
Contained 256 LCD elements x 2 stacked to
control group delay and amplitude.
nothing new.

jr

No if we can just... (0)

wbr1 (2538558) | about 7 months ago | (#44890159)

Solve the analog shark problem, we will be all set! Sounds like a good darpa project.

Hmm (0)

Anonymous Coward | about 7 months ago | (#44890195)

You know your country's science program sucks when you have to say:

"South African scientists are once again making noteworthy contributions to the world."

Power (0)

Anonymous Coward | about 7 months ago | (#44890983)

So, how much power can that LCD handle before it just melts?

Audio technology (0)

Anonymous Coward | about 7 months ago | (#44891181)

Does that mean they'll be able to create digital compact disc players in the future?

In Soviet Russia the ART priors YOU! (1)

Thor Ablestar (321949) | about 7 months ago | (#44892647)

There already has been something similar in Soviet Russia before 1990 but it was analog, not digital.

Russians have invented the laser TV projector where the lasing crystal was excited with scanning electron beam. Of course, it was purely experimental, monochrome and needed liquid nitrogen cooling but it worked spectacularly. The photo has been published in Russian popular RADIO magazine.

Vinyl vs. CD's (0)

Anonymous Coward | about 7 months ago | (#44893943)

This is wonderful. I can stop using my vinyl collection to focus lasers. Shiny new CD's are the wave of the future.

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