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This 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

This 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 ago
Go 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 ago
  Ironically 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 ago
    Lasers 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 ago
    The pulses are not entrained to software. They are inherent to the laser's design, such as with Q-switching.
    - vlovich123 2y ago
      I 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 ago
        Q-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 ago
  I'm incredibly curious as to what that even looks like. Where do you study? Can you give us a photo?
  - PaulHoule 2y ago
    See 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 ago
Seems 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 ago
Remember all those UFOs people were reporting? That was probably this, military took it over.

PaulHoule 2y ago

Go 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 ago
Ironically 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 ago
  Lasers 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 ago
  The pulses are not entrained to software. They are inherent to the laser's design, such as with Q-switching.
  - vlovich123 2y ago
    I 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 ago
      Q-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 ago
I'm incredibly curious as to what that even looks like. Where do you study? Can you give us a photo?
- PaulHoule 2y ago
  See 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 ago

Seems 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 ago

Remember all those UFOs people were reporting? That was probably this, military took it over.