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Science Technology

Cut Curiously Precise Holes With Femto-Lasers 37

Posted by timothy from the just-wanted-to-say-femto dept.
paymenow points out "this story at Science News Online about femto-lasers and how their novel 'cutting physics' allows much more precision than previous lasers. The technology is now finding applications in various industries including, biotech, automotive and laser eye surgery."
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Cut Curiously Precise Holes With Femto-Lasers More

Cut Curiously Precise Holes With Femto-Lasers

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  • Cool use for diabetics and hospitals (Score:3, Insightful)

    by phamlen ( 304054 ) <`phamlen' `at' `mail.com'> on Monday November 18, 2002 @08:02PM (#4702757) Homepage
    According to the article, the scientist demonstrated that the laser could cut his hand without causing pain!

    Heck, if they could make it cheap enough, that would be great in hospitals. Can you imagine if patients didn't need to be constantly pricked for blood?

    -Peter

    • Re:Cool use for diabetics and hospitals (Score:4, Insightful)

      by GigsVT ( 208848 ) on Monday November 18, 2002 @09:37PM (#4703209) Journal
      There is sort of an inherent problem with that. If the hole is too small to even hit any nerve endings, it's probably too small to let blood cells through.

      As it is, when my late grandmother was getting up in years, we had to prick her like three times with the heavy setting on the lanclet just to get blood.

      No sick jokes, I know you are comtemplating them! :)
      • "There is sort of an inherent problem with that. If the hole is too small to even hit any nerve endings, it's probably too small to let blood cells through."

        Actually, the article says otherwise, in an example where the researcher actually stuck his finger in to test it out -- "As the cut in his finger deepened and he felt no discomfort, Rode became convinced. When the blood started to flow, he yanked his finger away."

        I'm guessing that what's happening here is a result of the laser's ability to cut through with no damage to the surround areas. A nerve endings that gets destroyed or vaporized sends no signal -- but normally what happens is that nearby endings get activated by the microscopic tearing and damage done on the surrounding tissue. In this case, the surrounding tissue is completely untouched, so nothing happens.

  • Heheh (Score:3, Funny)

    by CableModemSniper ( 556285 ) <.moc.liamg. .ta. .odlapacnagol.> on Monday November 18, 2002 @08:12PM (#4702818) Homepage Journal
    Bring on the laser pistols. Slice off someone's arm they dont even notice because there is no pain. Awesome.
    • Or we could slice bin Laden in half in his cave bunker from a fighter. We could give up on studying bunker busting nukes.
    • Slice off someone's arm they dont even notice because there is no pain.

      Somehow I think they might notice during the month or so it would take :)

      -

  • Pulse Speed = Nanoscale Destruction? (Score:4, Interesting)

    by WeaponOfChoice ( 615003 ) on Monday November 18, 2002 @08:16PM (#4702831) Homepage
    Would increasing the pulse speed by 1kx have any effect upon the surrounding material, destructive effects that is. I realise that the pulses are fantastically short but surely going from a thousand fempto pulses a second (roughly 1 trillionth of a second on target) to a million (roughly 1 billionth of a second on target) should negate at least some of the benefits by dint of there being a shorter gap between the pulses to allow the highly ionised material to clear out. This didn't seem to be mentioned in the article so perhaps it's not an issue...
    • Increasing the rate of pulses (repetition rate) with the energy per pulse staying the same would indeed increase the thermal (destructive) load on the surrounding material. However, the question is, whether
      this increase would be significant. This really depends on where you start from (pulse energy) and what material you are looking at, i.e. on the actual numbers.

      However, increasing the repetition rate without reducing pulse energy is not easy. In fact, to get the pulse energy to levels where you can evaporate material you have to reduce the repetition rate.
      Usually fs-Lasers are built in the way that there is an "oscillator" that delivers short but weak pulses at a very high repetition rate (around 100 MHz). To get more intense pulses you have to amplify them, which usually results in a lower repetition rate, because for an amplification to take effect you have to apply it for a certain time (sum up several round trips of the pulse in the amplifier).
      For example in the laser I'm working with the oscillator delivers 20fs long pulses at 80MHz with each pulse having an energy of 5nJ. These pulses are fed into an "Regenerative Amplifier" that delivers 50fs pulses at 200kHz with each pulse having 5uJ of energy (a factor of 1000 more). The amplifier does this by letting a "seed" pulse from the oscillator run several times through an amplifier medium (a laser crystal) until a maximum pulse energy is reached and the amplified pulse is released to the output. You cannot however amplify every of the 80MHz pulses this way, because the amplifier medium has to regenerate ("charge up") before it can amplify again - that's where the name "regenerative amplifier" comes from.

      In some systems you can trade repetition rate for pulse energy, i.e. get more intense pulses by lowering
      the repetition rate (giving the amlifying medium more time to regenerate and therby reaching higher "charge" levels), but only in a limited range.

  • Femto lasers? (Score:4, Funny)

    by polyphemus-blinder ( 540915 ) on Monday November 18, 2002 @09:11PM (#4703100)
    Are those the kind that come out of hot chicks' boobs in Austin Powers?
  • I wonder-- might such devices be used to implement super-high-capacity optical storage?

    Of course, when you get things that small, dust/fingerprints would be a REAL big issue.

    Perhaps sealing a disc into a permanent caddy would do.

    Any math/science/optics geeks out there up to the challenge of computing what a theoretical "femto-burned" disc the size of a CD/DVD could hold, assuming you didn't have to worry about dust? (sealed in a caddy)
    • As a "math/science geek" who is dating an "optics geek" ... i can tell you this "femto-burning" is USELESS for increasing the data storage capacity of DVD/CDs. The constricting factor is the laser's wavelength. The laser's wavefront has a size that is propotional to the wavelength.

      Since a laser can't "see" objects (i.e. read data pits) smaller than the wavelength, computer chips are manufactured using Extreme-UltraViolet (EUV) lasers. However, size and $$$ are the current limiting factors for transitioning EUV to the desktop transition.

      Layering seems to be the way to go with getting more data on a disc (see a previous /. article on getting 87GB on a disc [slashdot.org])

  • Figures.... (Score:5, Funny)

    by KillerBob ( 217953 ) on Monday November 18, 2002 @10:47PM (#4703498)
    An even lighter touch is evident in recent work that demonstrates the femtosecond laser's potential for gene therapy. In the July 18 Nature, Uday K. Tirlapur and Karsten König of Friedrich Schiller University in Jena, Germany, described vaporizing tiny spots in the membranes of rodent cells immersed in a solution containing the gene for a fluorescent protein. The cells quickly repaired the holes--but not before the genes had apparently sneaked in, yielding cells that appeared normal except for their green glow

    All the technology in the world, and what do they use it for? To make glow-in-the-dark rats.
  • Enlighten me. This technology sounds as though its further away from cost effectiveness than a dotcom. How soon will be expect it to be cheap enough to use for all those fantastic applications?
    • Um ... according to the article, it's already in use for many applications: precise machining, removing cheap defects, LASIK surgery. If you're asking, "When can I get a femtosecond laser at home to carve cool designs on my cat," that might be a different story.

  • Waste Disposal (Score:1, Interesting)

    by Anonymous Coward
    From the description in the article, it basically
    describes the laser as an atomizer, tearing apart
    electron bonds. As technology improves, and energy
    becomes more plentiful, could this not be used to
    break waste down to it's elements, which could then
    be seperated, and recycled?
  • The cattle mutilation hoaxers are gonna love this.
  • This seems like it could be of massive use in the creation of nano-scale motors... imagine an ICE that could power your laptop for days, due to it's great HP to size ratio and the precision of the parts... it would need an ultra-tiny catalytic converter :)

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