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Femtosecond lasers create 3D midair plasma displays you can touch (2015)
- jagged-chisel 2y agoThis technology came up recently in conversation so I searched the web to see what became of it. All I can find are articles dating from summer 2015 and nothing of substance after that. I’m sure we can all come up with some reasons this wouldn’t be practical in many situations, but the tech seemed promising. Do any of you have knowledge of what happened here? Was it smoke and mirrors? Just really not practical? I would really like to read some details about why this seems to have vanished.
- PaulHoule 2y agoGo into a lab in the first floor of the physics building at my Uni and you are likely to find a femtosecond laser inside which sprawls over an optical bench which takes up most of the room. At the heart of it is a fiber laser that costs about $250,000 but they usually have added a lot of stuff to it. A femtosecond laser for medical use is about $400,000 https://crstoday.com/articles/2014-sep/pricing-the-laser-cataract-procedure https://crstoday.com/articles/2014-sep/pricing-the-laser-cat... which is one reason you might not see this become widespread.
- jandrese 2y agoIronically that seems promising. This could just be an engineering problem where the only people making the required laser equipment are only making lab/medical grade gear with enormous markups. It's possible someone comes up with a practical to manufacture solid state version that unlocks these displays for the masses. There is one consideration however where one failure mode for this device includes a situation where the processing locks up and leaves the laser pointed at a single spot continuously, burning a hole and possibly starting a fire.
- yetihehe 2y ago> where the processing locks up and leaves the laser pointed at a single spot continuously, burning a hole and possibly starting a fire. Already solved for 3d-printers locking up and starting a fire.
- PaulHoule 2y agoLasers used for laser light shows already have interlocks that will stop the laser if the mirror stops moving. My understanding is that femtosecond lasers have some parts that are physically large because they use prisms, diffraction gratings, and such, to spread out a pulse so the laser can effectively amplify it and then recompress the pulse to use it. See https://en.wikipedia.org/wiki/Pulsed_energy_projectile https://en.wikipedia.org/wiki/Pulsed_energy_projectile note a workable laser "gun" could plausibly be "set to stun" because if the energy of a pulse sparks the air near your skin or clothing, the plasma absorbs almost all the energy causing a plasma explosion which can knock you down plus cause severe pain from an electromagnetic pulse.
- emchammer 2y agoThe pulses are not entrained to software. They are inherent to the laser's design, such as with Q-switching.
- vlovich123 2y agoI think ops point still holds - actively modulated q switches could still have a failure that pushes the laser outside the safety parameters, no? I don’t think OP was necessarily suggesting a software failure.
- emchammer 2y agoQ-switching does not operate like a transistor's base. It is more like the charge pump on a camera flash. It will not produce a high-power pulse if operated outside of parameters. There are other ways with different physics but comparable principles.
- alt0_ 2y agoI'm incredibly curious as to what that even looks like. Where do you study? Can you give us a photo?
- PaulHoule 2y agoSee https://www.oist.jp/image/researchers-femtosecond-spectroscopy-unit-laser-lab https://www.oist.jp/image/researchers-femtosecond-spectrosco... or https://www.mp.aau.dk/research/laboratories/physics-lab/short-pulse-laser-labs https://www.mp.aau.dk/research/laboratories/physics-lab/shor... or https://hajim.rochester.edu/optics/sites/guo/virtual-lab.html https://hajim.rochester.edu/optics/sites/guo/virtual-lab.htm...
- deleted 2y ago[deleted]
- zonkerdonker 2y agoSeems like the tech is still likely alive and kicking in the military space: https://patents.google.com/patent/US20200041236A1/ https://patents.google.com/patent/US20200041236A1/ US Navy submitted a patent in 2018 for a jet-mounted plasma decoy projector, I'm sure they have many more applications that I wasn't able to find as well
- JumpCrisscross 2y ago> the tech is still likely alive and kicking in the military space I mean, it's a field that burns things that wander into it. I'm genuinely blown away this was considered for a display technology. It's closer to the risk profile of fireworks than an OLED.
- traverseda 2y agoRemember all those UFOs people were reporting? That was probably this, military took it over.
- chris_va 2y agoPfft, this is just a bunch of hot air. ... /s
- ffhhj 2y agoI remember IO2 Heliodisplay from around 2007. Now their site seems to be dead. > This holographic-style display works by projecting a 2D image onto a cloud of microscopic droplets (probably water, although this isn't confirmed) https://www.techpowerup.com/forums/threads/io2-launches-%E2%80%9C3d%E2%80%9D-screen.26657/ https://www.techpowerup.com/forums/threads/io2-launches-%E2%...
- Nursie 2y agoI followed them for ages, such cool tech for the early 00s when they first publicised it. But it never seemed to have gone anywhere. They were very cagey at first about the fact it used water vapour because they didn’t want people to think it was just projection onto a vapour screen when they had some sort of directed laser tech. It still needed the water though! If I were to guess why it didn’t reach any sort of momentum, I reckon they couldn’t control the costs or get the brightness good enough. But that’s really speculation.
- zoklet-enjoyer 2y agoUFOs
- dmbche 2y agoVery cool! How energy efficient could it theoretically be? Is it somewhat relatable to touchscreens, or are we talking thousands of times more power per pixel per second?
- Log_out_ 2y agoNow print circuitry mid air and energize..
- lainga 2y agoWeren't these things ear-splittingly loud from the constant formation of plasma balls in midair? That's what I recall from a demonstration In The Day
- mey 2y agoLooking into the plasma/laser paper and it mentions 77.2 dB at an insanely close 22mm distance. Background was 55.7. http://arxiv.org/pdf/1506.06668v1 http://arxiv.org/pdf/1506.06668v1 Page 9. It sounds (hah) like it wouldn't be pleasant if you have your head near a full display in operation, especially since the noise scales with the resolution/brightness. It would be interesting to see how quickly the noise drops off over distance. You are looking at something between a home sound system, vacuum cleaner, or highway traffic at that volume level. Tolerable but not pleasant.
- Filligree 2y agoI wonder if it could be modulated to function as a sound system?
- ben_w 2y agoYes. You may enjoy the similar use of Tesla coils: https://youtu.be/rd3bH_xNYYQ?si=TXO_kA0PZ6YkUZyt https://youtu.be/rd3bH_xNYYQ?si=TXO_kA0PZ6YkUZyt
- doublerabbit 2y agoPersonally I'm more the floppy drive fan. https://m.youtube.com/watch?v=8fh1CIupVXU https://m.youtube.com/watch?v=8fh1CIupVXU But Tesla coils are cool, as are van de graaff generators.
- aidenn0 2y agoA friend of mine built speakers that ionized the air and then used some mechanism (electrostatics? voice coil?) to move the air directly; kind of a coneless speaker. It didn't get that loud and made a lot of ozone.
- tflol 2y ago> The researchers found that a pulse duration that minuscule doesn't result in any appreciable skin damage unless the laser is firing at that same spot at one shot per millisecond for a duration of 2,000 milliseconds Haha so if this thing is misconfigured badly enough it can just melt you
- golergka 2y agoHow much does an 0-day cost for a device that can literally kill?
- kjkjadksj 2y agoAsk an automaker or an airline
- moffkalast 2y agoBoeing's hitman could not be reached for comment.
- throwaway562if1 2y ago[dead]
- deleted 2y ago[deleted]
- vlovich123 2y ago
- jpgvm 2y agoThere are many display technologies that just didn't make it to mass production. A favourite of mine is Field Emission Display technology. However they are largely irrelevant now because OLED essentially fill the same role.
- worldsayshi 2y agoMine is transreflective LCD. I just really want to be able to work with my laptop in the sun. https://en.wikipedia.org/wiki/Transflective_liquid-crystal_display https://en.wikipedia.org/wiki/Transflective_liquid-crystal_d... Here it's used on the Adam Tablet that never took off: https://www.youtube.com/watch?v=pGUKHDBoTEc https://www.youtube.com/watch?v=pGUKHDBoTEc
- Woovie 2y agoLTT just made a video about a modern display that is like this tech https://www.youtube.com/watch?v=c0TcGjzKbag https://www.youtube.com/watch?v=c0TcGjzKbag
- worldsayshi 2y agoInteresting! Although going for no backlight seem to make it about as impractical indoors as regular displays are outdoors?
- cycomanic 2y agoHi had an Adam, the idea (and display) was pretty cool, but the build quality and software was not that great. Eink really has taken over that niche though, so not sure I really miss those displays.
- worldsayshi 2y agoYeah it seems that TLCD never really got a chance to get developed properly. And Eink seem to me to have a lot of other clear drawbacks which makes it impractical for regular work use cases.
- cyberax 2y agoI have a slight eye damage in one eye from working with lasers that were just a bit outside the safe limits. And I realized that only years after getting it. So the last thing I want, is to be near unconfined lasers powerful enough to ionize the air.
- CodeArtisan 2y agoHow did you realized you had eye damage?
- BikiniPrince 2y agocheck engine light in the upper left hand corner of his vision.
- utensil4778 2y agoTypically you'll notice a persistent black spot in your vision. Particularly if you're looking at a bright field like a blank white page on your monitor.
- jessriedel 2y agoCite? My vague understanding of how vision works is that your brain will tend to interpolate over missing data rather than perceive it as black. So you need to actually test whether you can discriminate things in the affected field of view.
- atomicnumber3 2y agoVision is complicated. Everyone's vision experience is slightly different. So different people might notice different things.
- __MatrixMan__ 2y agoThis is not a citation, but... I have this spot in my right eye that resembles dead pixels. Just tiny blackness. If I let my eyes try to focus on it, it moves with my eyeball, so then they try to focus on the new location... ad infinitum. So they sort of jitter on a path upwards and to the right. I can only see it in certain lighting. Eye doctor couldn't see anything wrong with the area and suggested it might be a floater that got attached and would go away on its own within 6mo. That was 4yr ago and it's still around. It's not getting worse so it doesn't bother me, it just reminds me of the saa from the Wheel of Time. I would have expected interpolation versus vision artifacts as well, but apparently that's an "only sometimes" thing.
- bawolff 2y ago> However, a nanosecond-scale plasma burst still contains a significant amount of energy; you don’t want to go walking through one of these displays, because it will burn you. Yeah, i think that answers the headline question. Burning people is bad.
- throwaway562if1 2y ago[dead]
- jjk166 2y agoSo will touching a lightbulb, but we have those in abundance in the same application. I don't think that adequately answers the question.
- bawolff 2y agoWe don't usually have lightbulbs suspended mid-air at human height without some sort of protective case. I guess i assume the point here is to have no protective case since the article made such a big deal about touching the display.
- jjk166 2y agoThe overwhelming majority of lights are within human reach with no protective casing. There might be a lampshade to diffuse the light, and some frame to physically support the bulb, but nothing to stop a human hand from reaching in and touching it. Hell installing and replacing bulbs is typically done with bare hands. Free hanging bulb lights used to be quite common in closets and basements.
- twic 2y agoWhile we're on the subject, what happened to uBeam?
- kragen 2y agosame thing that happened to theranos, just in a lower-key fashion; they hadn't figured out how to do the thing they said they'd figured out how to do, and possibly nobody ever will in my book that makes them a fraud, though there are clearly a lot of ai company founders who disagree
- Trevor908 2y agoThey collapsed, because they couldn't deliver anything remotely close to what was promised. IMO they knew all along it was a fraud and just kept the story going as long as they could. I think they renamed themselves "sonic energy". Excellent thread on eevblog: https://www.eevblog.com/forum/chat/the-ubeam-faq/1900/ https://www.eevblog.com/forum/chat/the-ubeam-faq/1900/ Now Perry is pumping some neuro-ai-sleep-aid nonsense.
- dotnet00 2y agoReminds me of the story from a few years ago where the US military was looking into scaring people via screaming balls of plasma, which gave rise to the joke that the CIA was trying to make religious extremists think their god was talking to them using the tech. https://newstarget.com/2018-04-24-u-s-military-creating-non-lethal-laser-that-projects-screaming-balls-of-plasma-in-the-air-to-scare-enemies.html https://newstarget.com/2018-04-24-u-s-military-creating-non-...
- farkanoid 2y agoI remember this! I'm glad someone else does too.
- farkanoid 2y agoI often wonder the same about the technology used in a mysterious video that appeared on youtube about 15 years ago titled "Laser Induced Plasma Channel". It appears to be an area denial weapon that uses femtosecond lasers to guide electric arcs across a hallway (think a metre-long ridiculously straight Taser discharge). The video had no description and comments on it were never answered - it was recently removed by the uploader, but there seems to be a reupload on DailyMotion[1] from 9 years ago. [1] https://www.dailymotion.com/video/x31ovvi https://www.dailymotion.com/video/x31ovvi
- Animats 2y agoSee-through displays show up in movies so that the viewer can see the actors' faces. Not because see-through displays are useful.
- ErneX 2y ago(2015)
- 201984 2y ago(2015)
- max_ 2y agoIf you're interested in that project. Here is an equally cool project form Voxon Photonics. That you can buy today and is also very safe.[0] [0]: https://voxon.co/ https://voxon.co/
- jcims 2y agoThis page has been around for a while. If you watch the YouTube video, you can see the skin on the person’s finger get burnt as they touch the little tiny plasma balls. https://youtu.be/AoWi10YVmfE?si=1zzwNba9A1l9Y2ld https://youtu.be/AoWi10YVmfE?si=1zzwNba9A1l9Y2ld
- vonzepp 2y agoThis is quite hard to do safely. Generating air breakdown with IR femto requires a reasonable amount of fluence. They are probably using galvo scanners to shift the beam in xy, but to get the required intensity they have to also shift the focal plane. Given the distances they are projecting away from the car that NA is low meaning they would need a reasonable power. Probably why they are running it at 1kHz. Given its 2015 it is probably a ti-sapphire at 80fs, galvos and an optotune lens. The reason this isn't a thing is that it very hard to make this eye safe.
- jagged-chisel 2y agoThis was supposed to be Ask HN but I didn’t realize I was on the wrong page for Ask submissions. So the title was changed to reflect the article. Anyway, my comment asked the question and we got some discussion, so it’s all good.
- m3kw9 2y agoUntil a kid put his face in it for fun
- bilsbie 2y agoWhatever happened to the idea of sending electricity through air with this technology? One application I heard of in the 90s was a long range taser.
- ForOldHack 2y agoQue ads.
- RIMR 2y agoOP forgot to include it in the title, but this is from (2015).
- thesh4d0w 2y agoWorth calling out this article is from 8 years ago.
- nirav72 2y agoI’m imagining blade runner style giant holograms above buildings if this tech matures
- Cadwhisker 2y agoThe video shows slightly burned skin on the tip of his finger where he has been touching the "display".
- awinter-py 2y agothe large kind also do this in a sense
- alwa 2y ago(2015)
- deleted 2y ago[deleted]
- ranger_danger 2y agoYou can also use femtosecond lasers and a streak camera to film the speed of light: https://www.youtube.com/watch?v=7Ys_yKGNFRQ https://www.youtube.com/watch?v=7Ys_yKGNFRQ Maybe one day something like this can be used to have true light-field cameras without microlens arrays (like Lytro had).
- karunamurti 2y agoI just want to point out holodeck episode in Star Trek preceded Star Wars by 3 years.
- aidenn0 2y agoIt was the animated series, if anyone else is like me and could not for the life of themselves remember a holodeck in the original series (Thanks Memory Alpha!).
- denton-scratch 2y ago> laser-induced plasma displays that ionize air molecules to create glowing points of light. The New Scientist used to have a column inside the back page called Daedalus. It usually described some kind of weird or wonderful "invention" that probably wasn't practical. One of them was for street lighting: you'd have pairs of ultraviolet lasers on either side of the street, intersecting in mid-air. The pairs of lasers would have frequencies that were not exactly the same, so that at the point of intersection lower-frequency "beats" would occur. If the frequency of the beats were adjusted to match the excitation energy of (e.g.) O2, the oxygen would emit light. Another Daedalus "invention" I remember was to use plant tropins to control the growth of wood. You could then grow e.g. an armchair, or a table, or even a house. No glue needed, no saw needed. I don't know who used to write that column.
- elric 2y agoControling the growth of wood in that manner is a pretty common fantasy trope, usually of the Elven variety. Or treesinging in Wheel of Time, for example. It's one of those that occasionally pops into my head. Would be pretty neat from a CO2-sequestration point of view, but unless the wood is stressed appropriately during growth, the resulting furniture (or housing) would likely crumble pretty easily.
- cess11 2y agoBending young trees and keeping them in place mechanically to make them grow into interesting or useful shapes is quite viable, probably not to make an armchair but possibly pieces for constructing one, or something simple, like a one-piece walking stick.
- keepamovin 2y agoThat's it, we've got holograms now. So cool!!!! :) Hahaha! :)
- jojobas 2y agoCtrl-F ozone - nothing. Hello cancer my old friend.
- mapt 2y agoThey're thermally heating up the air with lasers? Doesn't a white-hot atmospheric plasma emit plenty of hard UV? Or is this some kind of specific spectral line emission that the photos don't do justice?
- ericyd 2y ago> it’s not that crazy to look at this project and believe that such a gadget* might not be so far away. 9 years later, I think we can safely say yes, it is crazy to believe that such a gadget might not be so far away. *quotation was referring to wearable holographic displays made with this tech
- pfdietz 2y agoHow much NOx would this generate, I wonder.