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NIST scientists create 'any wavelength' lasers (nist.gov)

by rbanffy 193 comments 421 points
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193 comments

[−] nabakin 26d ago

> When it comes to information transfer and processing, light can do things that electricity can’t. Photons — particles of light — are far zippier than electrons at working their way through circuits.

Electrons themselves don't move at the speed of light, but information transfer (i.e. communication) via electrons does happen close to the speed of light.

A subtle, but important, distinction that's often misunderstood and means computational performance gains would probably come from bandwidth, not latency.

[−] Hikikomori 26d ago
About 0.6c for cat6 cables, different types of cables can be slightly faster. Speed of light in fiber is also 0.6c due to the refractive index of the core.
[−] derefr 25d ago
Is that through solid-core fiber? Because hollow-core fiber also exists.
[−] Hikikomori 25d ago
Yes. It does, but it's not widely used, it barely just got out of the lab.
[−] thayne 25d ago

> but information transfer (i.e. communication) via electrons does happen close to the speed of light

Speed of light in the medium, not speed of light in vacuum.

[−] NL807 26d ago
In electric circuits, information is transmitted through the electric field, which itself is close to the speed of light.
[−] tempaccount5050 26d ago
Nope, it's 1/2 - 2/3 the speed of light depending on the metals used.
[−] KK7NIL 26d ago
The velocity factor is usually 0.6-0.7, never seen it as low as 0.5.

And it's set by the dielectric, not the conducting material.

[−] spwa4 26d ago
You're both wrong. It's true that the first whisper of movement travels at the speed of light, but the time until the flow stabilizes (which you WILL need to wait for in electrical chips) is actually slower than the "speed of electricity".

Oh and also: currently the idea behind on-chip lasers is interconnects that don't have this limitation. For example, PCIE is looking to build optical interconnects, which will do the equivalent of bringing every GPU 10x closer to the memory.

Optical computation would require that light switches light transistors on and off, which doesn't seem to be possible with this technology. This is optical computation in the sense of allowing light beams to be produced according to formulas.

[−] BenjiWiebe 25d ago
Why do you need to wait for it to stabilize? You can keep changing the voltage at one end of the connection even if you have megabits of data currently in transit, without waiting for it to stabilize. Yes, you'll need to do impedance matching. Yes, that's a solved problem. Transmission lines.
[−] sbuttgereit 25d ago
Looking at the discussion below this comment, I'd just add this video by AlphaPheonix:

https://www.youtube.com/watch?v=2Vrhk5OjBP8

Good discussion in the comments there as well.

[−] dtgriscom 26d ago
That picture of the wafer with a rainbow of shapes is very misleading. It suggests that the various colors you see on the chip is the various colors the lasers can emit, which is wrong; it's just diffraction, and has nothing to do with the topic of the article. (But, PR people gotta PR...)
[−] adzm 26d ago
Everyone talking about magenta and brown, but you can see an illusory color right now even without lasers! https://dynomight.net/colors/ behold, some kind of hyper-turquoise
[−] mapt 26d ago
Is there a single person here interested in photonic computing that wants to explain to the class if there's any "there" there?
[−] spaqin 26d ago
That's most certainly good news (depending on the final cost) for ion trapping quantum computing - the wavelength of the laser they require to trap an ion depends on the molecule chosen, and most setups are expensive, finicky and difficult to calibrate, or sometimes messy if it's a dye laser.
[−] jjmarr 26d ago
I'm excited for new displays where instead of RGB primaries that can only show a triangular subset of possible colours, we have dynamic primaries that can combine to show almost any colour.
[−] krenzo 26d ago
[−] HNisCIS 26d ago
Something to be aware of, the laser safety goggles used by lab workers, pilots, soldiers etc are based on the premise that lasers only occupy extremely specific and narrow parts of the spectrum so by just blocking those little bits, you can get a very effective pair of glasses that doesn't significantly effect visibility. Arbitrary waveform lasers cause problems here.
[−] wizardforhire 26d ago
Just read the article and didn't see anything about building an actual laser… what details the article has (and its scant) its seems they took a fluorescing layer and sandwiched with a color wheel and added the additional wiring and control circuitry… (Obviously more nuanced and interesting physics but still…) cool and practical, but not a diode and definitely not a laser… I could be wrong and would love to be!

… now, if that setup could be drawn out into a fiber laser as cladding with a wide spectrum neural amplifying core (if such a material exists) that could maybe be something idk

[−] xbmcuser 26d ago
Is this the cheaper way to get to extreme uv lithography as from what I understand the largest bottle neck for China has been to get the exact wavelength needed to go small enough?
[−] xphos 26d ago
I don't know to much about photonics but if they ever figure out the boolean algebra and register storage it would be really cool. You have 1 photo cpu core but just use different wavelengths for different threads running in the core. I am sure its way more complex than that but articles like this make you dream about how much we don't know
[−] SEJeff 26d ago
The US Navy has been working on their idea of a holy grail they have deemed the free electron laser[1]

[1] https://boeing.mediaroom.com/2010-03-18-Boeing-Completes-Pre...

[−] wyager 26d ago
The final frontier of display tech (as far as being able to elicit any physiologically possible eye response) is a pair of tunable lasers. You really can't go much farther than that for emissive displays! We're almost saturated (no pun intended) on useful resolution, so I expect color to be the next area of focus.
[−] aftbit 26d ago
Cool, can I get a "proper" yellow diode laser from this? What's the efficiency look like?
[−] anigbrowl 26d ago
I wonder if photonic computing with variable wavelengths essentially gives you a float type in silico.
[−] DarenWatson 26d ago
It’s really fascinating electrons took 60 years to go from chip to a smart device and if photons follow the same thing then we just fired the starting gun. It’s really interesting to see tantala material takes a single laser color in and spits out to a full rainbow.
[−] thayne 25d ago
Does this mean they can create a chip that emits light at a specific frequency they choose? Or the chip can emit a programmable frequency that is controlled "at runtime" so to speak? I wasn't able to figure that out from the article.
[−] spacedoutman 26d ago
My first thought is this will be used as a weapon to bypass protections against specific wavelengths
[−] jcims 26d ago
Can each device vary the color or is it fixed based on how it’s built? Seems the latter?
[−] evo 26d ago
I wonder if this is a nuclear proliferation risk--could it be used for AVLIS/SILEX?
[−] jagged-chisel 26d ago
The "shrinking" circle: I did as asked and clicked the image to see the animation. I saw no shrinking. My eyes did fatigue and I saw the border between the red and green become a blurred gradient.

What should I have experienced?

[−] MeteorMarc 26d ago
Title is misleading. This is about integrated optics that can do "computation" on the frequency of laser input using all kinds of nonlinear optical effects.
[−] himata4113 26d ago
since the light range is so high, technically speaking as the technology improves does that mean we could end up sending petabytes a second over a single fiber optic core?
[−] deepsun 26d ago
Would I finally be able to see bright brown?
[−] foxes 26d ago
From reading assume they mean wavelength of ~ visible light.

I too would like a microwave or gamma laser

[−] analog8374 26d ago
can they do microwave?

if you do the exact right color you can make certain things melt very precisely.

[−] ginko 26d ago
With two of these you should be able to display any color in the CIE colorspace.
[−] cheschire 26d ago
Yes but can it do any color a mantis shrimp would like?

https://theoatmeal.com/comics/mantis_shrimp