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

• jcul

  yesterday at 11:31 PM

  The whole idea of colour and light frequency is fascinating.

  These are just frequencies of light, but the subjective experience of them is so much more.

  And the whole thing of my perception of "red" or what I call "red" could be very different to someone else's subjective perception. But we would both call it red and associate it with the same thing, fire, love, heat, danger etc.

  • sgc

    today at 1:23 AM

    > what I call "red" could be very different to someone else's subjective perception

    It's worth noting that is true of virtually everything we know. >>This is a very simple sentence.<< Anybody who understands English, 'understands' it. But what it means to understand it is perhaps completely different for each person. As long as they fit into the same place in their worldview (Lewis Caroll's Carrollian syllogisms come to mind), practically it often doesn't matter beyond recognizing the wonderful uniqueness of each human being. Likewise, unless somebody is color blind or perceives more colors than others (tetrachromats), it doesn't matter since the relationships between the different concepts or colors will be analogous amongst most people - so a common understanding within the differences is possible. Or perhaps it is more precise to say that there are so many data points in color perception or anything we know, that despite the minor differences in relationships, we understand each other because the differences must be minimal given the practically unlimited data points constraining our perceptions. In fact, when people's perceptions of things vary too much, they can be classified as mentally ill even if they understand many things perfectly well.

  • da_chicken

    today at 12:09 AM

    I think it's important to remember that we're not perceiving some fundamental aspect of light. We're perceiving how the photosensitive portions of our retina convert light to stimulus, and how our brains construct a meaningful image from that stimulus in our mind.

    Like film photography doesn't happen in the lens or the world. It happens in that photosensitive chemical reaction, and the decision of the photographer.

    • TomatoCo

      today at 12:26 AM

      It reminds me of how vinyl records are fairly lossy, but they provide a superior experience in some cases because those limitations have been accounted for during the mastering process.

      It's an entire pipeline from photomultiplier to recording medium to the inverse process and everything is optimized not for any particular mathematical truth but for the subjective experience.

      • hank808

        today at 1:30 AM

        Most records these days use CDs as masters, sadly.

  • awesome_dude

    yesterday at 11:39 PM

    But also - colours don't exist without a name

    eg. Before Orange, there was only shades of yellow or reds

    • jjk166

      today at 12:12 AM

      The colors most certainly exist without the name. You may have described the fruit as being a weird shade of red, but if someone held up something red and said "so it was this color" you'd say no. Conversely if someone held up something that was actually orange colored, you'd say "yeah it was that color."

      Similarly, you may have no idea what the name is for the color of a Tangerine, but you know what that color is. You might describe it as a dark orange. If I say the name for it is coquelicot, you can look up coquelicot and see if it matches the color you picture in your mind.

  • huflungdung

    yesterday at 11:58 PM

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• twodave

  today at 12:59 AM

  FYI if you get ocular/retinal migraines like me then the exercise in this article might be a bad idea.

• junon

  yesterday at 11:04 PM

  For those not seeing it or only seeing a little, stare at it for a while then shake your head (or your phone) just a bit.

  • marzell

    yesterday at 11:14 PM

    Also there are other variants and tricks around this for other colors as well https://en.wikipedia.org/wiki/Impossible_color

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.

Is there a single person here interested in photonic computing that wants to explain to the class if there's any "there" there?

• nine_k

  yesterday at 10:39 PM

  Immediately:

  * You can pack many more different colors into fiber optic communication lines. Every color carries a few tens of GHz in modulation, but the carrier light is in hundreds of THz; there's a ton of bandwidth not used between readily available colors.

  * You can likely do interesting molecular chemistry by precisely adjusting laser light to the energy levels of particular bonds / electrons.

  * Maybe you can precisely target particular wavelengths / absorption bands for more efficient laser cutting and welding, if these adjustable lasers can be made high-power.

  • summa_tech

    today at 12:15 AM

    Fiber has fairly narrow windows in which it is as transparent as it needs to be to go long distance. We're already pretty good at filling these windows with conventional semiconductor lasers.

    What this is actually interesting for is being able to access arbitrary atomic transitions, many of which are outside the range of conventional semiconductors (too short, usually - there's a big hole between green and red for semiconductors). That's why they talk about quantum stuff.

  • suzzer99

    yesterday at 10:49 PM

    * Concert lasers just got a lot cooler.

    • inetknght

      today at 12:20 AM

      Concert tickets will still remain very hot though.

• db48x

  yesterday at 10:15 PM

  It’s like any other fundamental research: you don’t know how much it’s worth until people start using it to solve real problems. This is something that is literally impossible to guess ahead of time. The most abstract mathematical techniques could turn into a trillion–dollar industry (number theory begat RSA encryption which now underpins _everything_ we do).

  But I will say that precise control of laser wavelength is critical to today’s communication technologies. I doubt their new techniques will be useless.

  • QQ00

    yesterday at 11:47 PM

    Hopefully the billions money in AI will find some of its to turn this into real life applications. AI inference would love some more faster more efficient communication.

    I mean, Photonic computing already got the attention of these big tech companies.

• topspin

  yesterday at 10:30 PM

  There is there there...

  The substance is they've created a way to fabricate a device that can make the optical frequencies they wish. That is useful: it means a designer isn't limited to frequencies that are economic to generate with existing techniques, which is a constraint that lasers currently struggle with: low cost, compact, efficient laser sources (the kind that fit on a chip, and are fabricated by cost effective processes,) only exist for a limited number of frequencies.

  The story is typical tech journalism pabulum, but the underlying paper does discuss efficiency. It's about what you'd expect: 35 mW -> 6 mW @ 485 nm, for example.

  An obvious use case is multimode fiber communication: perhaps this makes it possible to use more frequencies for greater bandwidth and/or make the devices cheaper/smaller/more efficient. But there are other, more exotic things one might do when some optical frequency that was previously uneconomic becomes feasible to use at scale.

  • criticalfault

    yesterday at 10:34 PM

    I wonder if this could also work for (e)uv

• dado3212

  yesterday at 10:37 PM

  I think it's more relevant for quantum computing. The ions we choose for ion trap quantum computers are in part due to what wavelengths are excitable by modified telecom lasers, because they're the wavelengths that are easiest to produce and where the most research/stability/miniaturization has been focused. If the laser wavelength is configurable to this degree then it no longer becomes a constraint, and maybe you can choose single ions with different characteristics.

• Lerc

  today at 12:29 AM

  Not an expert in the field but it seems to me the key points are.

  Generating any wavelength. (this article)

  Accurately measuring wavelength. (otherwise there's no information benefit to arbitrary wavelength generation)

  Wavelength insensitive holographic gates. (If they work on that frequency, and in a way that does not change the frequency) I don't know what properties such devices currently have

  Assuming all of those, your ability to compute increases to your ability to distinguish wavelengths.

  You could theoretically calculate much more in a way you could never detect, but then you get into some really interesting tree falling in a forest issues.

• 2ndorderthought

  yesterday at 10:36 PM

  Depends on the cost. We already have variable wavelength lasers. We have had them for years. They are currently expensive, large, and not the easiest things to control electronically.

  I have an application in mind for this technology outside of photonic computing. Again, it depends entirely on price, tunability, bandwidth of the profile, etc. My understanding of the photocomputing field is limited but I never thought the major issues were wavelength related? Maybe someone can educate me.

  If anyone wants to send me one of these I would be pumped.

• brcmthrowaway

  yesterday at 10:10 PM

  There's a lot of people here with esoteric knowledge of lasers, because they're generally incredible devices (along with masers). Someone should be able to comment.

  I wish we had a large laser manufacturing ability in the West. I would say 95% of lasers of all kinds are manufactured in China.

• SilentM68

  yesterday at 10:46 PM

  [flagged]

> 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.

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

If only.

https://en.wikipedia.org/wiki/Gamma-ray_laser

The actual paper: https://arxiv.org/abs/2509.08092

My first thought is this will be used as a weapon to bypass protections against specific wavelengths

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.

• packetlost

  today at 12:06 AM

  Neutral atom too. You need fairly clean light to pump atoms into Rydberg states

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?

• deepsun

  yesterday at 11:39 PM

  State for longer. It starts shrinking only after a minute.

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?

• tbrownaw

  today at 12:13 AM

  Visible light is a bit less than a petahertz, so no.

  • osamagirl69

    today at 12:28 AM

    Would you care to explain how the NICT guys achieved 402Tb/s through a single (50km long!) fiber back in 2024 then? It seems like another factor of two would easily be in reach if they could extend their setup into the visible.

I wonder if this is a nuclear proliferation risk--could it be used for AVLIS/SILEX?

Can each device vary the color or is it fixed based on how it’s built? Seems the latter?

• 2ndorderthought

  yesterday at 11:26 PM

  I believe you are right.

Cool, can I get a "proper" yellow diode laser from this? What's the efficiency look like?

Would I finally be able to see bright brown?

• nine_k

  yesterday at 11:54 PM

  It's called orange. Much like bright gray is called white, and bright teal is called turquoise.

  • rafram

    today at 12:15 AM

    Light brown is called tan. Dark and light oranges exist too and they’re not exactly the same as brown.

    • drivers99

      today at 1:33 AM

      See Technology Connections' video about Brown: https://www.youtube.com/watch?v=wh4aWZRtTwU

      He says brown is perceived when you see an orange-wavelength light that is significantly darker than its surroundings, providing the necessary context for your brain to interpret it as brown.

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

Yes but can it do any color a mantis shrimp would like?

https://theoatmeal.com/comics/mantis_shrimp

• Tade0

  yesterday at 11:09 PM

  The Mantis Shrimp most likely sees very much like us (or birds, snakes), it's just that its brain is too small to integrate signals from just three types of cones, so it evolved a whole rainbow of cones.

  • JumpCrisscross

    yesterday at 11:11 PM

    Huh. Anywhere you'd suggest I can read more about this?

• skoocda

  today at 12:09 AM

  This misses one of the best mantis shrimp facts.

  One of its receptors only detects circularly polarized light

  But the only thing we know of, in the entire natural world, that emits circularly polarized light... is the reflection off the shell of the mantis shrimp.

0.1nm please. It's x-ray lithography time!

I'll take one in gamma please.

• Retro_Dev

  yesterday at 11:04 PM

  A gamma wavelength handheld laser would be cool; "and on this petri dish, we see a dot of cells instantaneously develop cancer"

  • __MatrixMan__

    today at 12:03 AM

    At high energies I think you could point two at a spot in space and get antimatter where the beams cross (also matter, and then an explosion... see the Breit-Wheeler process).

    We have a hard enough time building shipping-container sized devices that reflect extreme ultraviolet though... so I think a handheld gamma ray laser is off the table for this century.

Very cool stuff. I regret wasting my life in software when I see other fields still doing interesting work.

can they do microwave?

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

• Aboutplants

  yesterday at 11:18 PM

  An application that came to mind is tunneling (through rock and earth). You could absolutely tune the wavelength to whatever material your drilling through absorbs best, to help ease and speed. Would need a good amount of energy but I could see that utilized in some fashion in the next 10-20 years

• BigTTYGothGF

  yesterday at 10:34 PM

  https://en.wikipedia.org/wiki/Maser

  • analog8374

    yesterday at 11:07 PM

    thanks, I'm familiar. But it doesn't answer my question.

But can it produce magenta?

• ivanjermakov

  yesterday at 10:59 PM

  Not every color has a corresponding wavelength, rather a combination of wavelengths.

  https://en.wikipedia.org/wiki/Color_vision

  https://en.wikipedia.org/wiki/CIE_1931_color_space

• dnnddidiej

  yesterday at 10:27 PM

  Magenta is the Doom of colour lasers by the look of it.

What if I like magenta? Or brown?

• zamadatix

  yesterday at 10:20 PM

  Pedantry for pedantry, you're in luck as the title says they created 'any wavelength lasers' not 'any wavelength laser' so you can make any such combos you like rather than the fixed set now (if true) :p.

• dullcrisp

  yesterday at 10:21 PM

  Can I interest you in indigo or violet? Or a nice orange?

  • dnnddidiej

    yesterday at 10:26 PM

    Genuine q: how close can you get to magenta with the rainbow?

    • nine_k

      yesterday at 10:33 PM

      What we call "magenta" is the sensation of both red and blue color-sensitive cells in the eye being excited at the same time. There's no single wavelength that produces this effect (unlike e.g. yellow). The closes you can get is violet, which looks faint to the eye.

      A rainbow gives you both red and blue; mute everything else, and you'll get magenta. That's what magenta pigments do when illuminated by white light (which is a rainbow scrambled).

      • dyauspitr

        yesterday at 11:09 PM

        Saying a wavelength doesn’t do it doesn’t make any sense. If you can perceive it visually, a wavelength is doing it.

        • nine_k

          yesterday at 11:24 PM

          Two wavelengths do it; one does not suffice. It's like a perfect fifth can not one note.

          • dyauspitr

            yesterday at 11:25 PM

            The interference is a wavelength too. Maybe not pure but it is one. Afaik they cannot be interpreted as two separate wavelengths and then “brain combined” when the aperture (the retina) is so small.

            • redsocksfan45

              yesterday at 11:26 PM

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        • redsocksfan45

          yesterday at 11:23 PM

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    • compass_copium

      yesterday at 10:35 PM

      Not very! This is on the "line of purples".

      Here's a nice visualization of color perception (there are more modern ones, but we used the 1931 color space when I was working in the field). The horseshoe shape on the outside is the single wavelength colors.

      https://en.wikipedia.org/wiki/CIE_1931_color_space

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