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Highly Directional Terahertz Laser Demonstrated 125

Posted by kdawson
from the break-out-the-tinfoil-underware dept.
eldavojohn writes "A new paper published this week in the journal Nature Materials announces a successful demonstration of highly directional terahertz semiconductor lasers. You might not think it's a big deal that some Harvard and University of Leeds researchers (funded partially by the US Air Force) figured out how to better direct lasers; but this means the ability to see what's in someone's pockets and clothing, at a distance of possibly hundreds of meters, or farther. The big benefit is that they are lower in energy than X-Rays and are less invasive, since they cannot pass through water or metal. Coming soon to an airport near you or buzzing around on board a drone in civilian airspace?"
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Highly Directional Terahertz Laser Demonstrated

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  • by mangu (126918) on Sunday August 08, 2010 @04:04PM (#33182662)

    The Wired article has a sidebar with "Featured Articles", one of them is "Flying Cars are Coming".

    Does this tell anyone about how soon this laser will have real world applications?

    • by Dunbal (464142) *

      Does this tell anyone about how soon this laser will have real world applications?

      I guess it all depends on which side of the fence you're on. I consider myself open minded. I can see regular cars equipped with these, shooting down the flying cars with a snigger. On the other hand, I can see them mounted on flying cars too. Strafing runs through heavy traffic could make for a very interesting drive to work in the mornings.

      Ahhh, so many possibilities.

      • by Anonymous Coward
        "Strafing runs through heavy traffic could make for a very interesting drive..."

        U.S. society: Violence-minded people want to spend taxpayer money for endless war.
        • Well, it works both ways. In my entertainment, I'm violence-minded, but in reality, if I were ever to harm another human being, politicians -- especially those who start wars -- would be towards the top of my list.

        • by Dunbal (464142) * on Sunday August 08, 2010 @05:16PM (#33183150)

          U.S. society: Violence-minded people want to spend taxpayer money for endless war.

                Oh no, this would be privately funded! :)

        • by xmundt (415364)

          Greetings and Salutations...
          Reminds me of a great wargame from the late 70s/early 80s called "Car Wars". Basic idea was that you COULD have that gatlin gun mounted on your vehicle, and, blow away the other idiots on the road. There was also a crossover with AD&D where, among other fun things (can you say Fireball Spell?) you could invoke a mechanic demon who was outside time so could rebuild your entire car while it was traveling down the road at 120 MPH.

    • Does this tell anyone about how soon this laser will have real world applications?

      Especially since the terrahertz waves still won't show what's hidden in folds of flesh, beneath pendulous breasts, or in body cavities. If the objective is real security through scanning people (as opposed to costly and annoying theatrics), it would have to be a lot more intrusive.

    • by PopeRatzo (965947) *

      real world applications?

      My cat would love this thing. You should see how she chases the laser all over the house.

      And what fun for me if she catches this one!

      • by hoggoth (414195)

        I hope you know that while your cat is playfully chasing that little dot the invisible infra-red light coming out of that toy at several times the power of the visible beam may blind your cat.

        • Re: (Score:3, Informative)

          by Foobar_ (120869)

          If it's a laser pointer made with a red (670, 650, 635 nm), blue (445 nm), or violet (405 nm) laser diode, there's absolutely no infrared emitted.

          If it's a properly made diode-pumped solid-state laser pointer (532 nm green, 473 nm blue, 404 nm frequency doubled violet) there's an infrared filter in the optical train which removes the large amounts of invisible pump light and leaves only the visible green.

          If it's a crap green laser pointer (e.g. the "high power" green pointers sold on eBay and the like) then

  • Welcome our new spy laser wielding overlords.
  • by fahrbot-bot (874524) on Sunday August 08, 2010 @04:08PM (#33182696)

    The big benefit is that they are lower in energy than X-Rays and are less invasive, since they cannot pass through water or metal.

    ...sharks disappointed.

  • Oh God (Score:3, Funny)

    by CasualFriday (1804992) on Sunday August 08, 2010 @04:10PM (#33182704) Homepage
    So now airport security officers can see my genitals from hundreds of feet away?
    • Re:Oh God (Score:5, Funny)

      by EdIII (1114411) on Sunday August 08, 2010 @04:29PM (#33182848)

      So now airport security officers can see my genitals from hundreds of feet away?

      Even with that technology, I still don't think we will be able to find your genitalia. Sorry.

    • Re:Oh God (Score:5, Funny)

      by Beardo the Bearded (321478) on Sunday August 08, 2010 @04:36PM (#33182920)

      Dude, I'm 33 years old. I'm married and I've got two kids.

      It has been years since anyone has been interested in my genitals, and I kind of miss the attention.

      • Dude, I'm 33 years old. I'm married and I've got two kids. It has been years since anyone has been interested in my genitals, and I kind of miss the attention.

        I think there are a lot of people with delusions of being supermodels.

        Most of the people I see on planes are ugly as hell and getting me to stare at them naked all day on a scanner would require some serious compensation.

        • Re: (Score:3, Insightful)

          by Surt (22457)

          Yeah, if you have to be a scanner, definitely be a scanner for the first class passenger line.

          • Because old rich people are attractive?
            • Re: (Score:3, Interesting)

              by Surt (22457)

              Their trophy girlfriends tend to be. I mean, there's no avoiding scanning some of the wrong sex unless you're bi, so assuming you're a horny male heterosexual screener, your odds are best with the first class passengers.

              • by rdnetto (955205)

                Depends on your definition of attractive. Beauty is in the eye of the beholder and all that.

                • by Surt (22457)

                  Well, start with the most common definition in our society, assuming that is most likely to intersect with the largest portion of the potential screener population.

                  • by rdnetto (955205)

                    Why use the most common definition? If it's for the benefit of the scanner, use their definition of attraction. Of course, then it becomes much harder to give a generalised answer.

                    • by Surt (22457)

                      It's for the benefit of the abstracted, hypothetical scanner. Since I wanted to make a generalized statement about what would be good for the scanner, I have to treat him as a singular construct, best represented by the average views of the class.

        • Some people just don't like to be exposed. It's not always a matter being oggled. It may be perceived or real inadequacies. http://cbs4.com/local/tsa.screener.arrest.2.1681203.html [cbs4.com]

      • Re: (Score:2, Funny)

        by CasualFriday (1804992)
        This is unbelievably depressing. also, I love how there is a button at the bottom of your post that says "parent".
    • by wagnerrp (1305589)
      Yes, but you can still hunt them down and beat them up in the parking lot when they make jokes.
    • by Chih (1284150)
      No, you'll still have to be pretty close ;)
    • by Zerth (26112)

      So now airport security officers can see my genitals from hundreds of feet away?

      Worse, they'll know who to pull out of line so they can nick the most change during the pat down.

    • by HTH NE1 (675604)

      It's the Nude Laser [imdb.com]! We need to get Agent 86 [imdb.com] on this.

      Oh, he is? How about Agent 86.1 [imdb.com]?

      Oh, ugh! Um, any chance we have an Agent 99.1?

  • PSA (Score:1, Informative)

    by JamesP (688957)

    For non-visible wavelenghts (or anything near it) it's not a LASER it's a MASER http://en.wikipedia.org/wiki/MASER [wikipedia.org]

    • Re:PSA (Score:5, Informative)

      by Daniel Dvorkin (106857) * on Sunday August 08, 2010 @04:25PM (#33182820) Homepage Journal

      The "M" in MASER stands for "microwave." The waves used here are non-visible, sure, but they're shorter than microwaves, closer to what's usually called infrared. And "laser," no longer capitalized, has entered the language as a word for any device that emits a beam of coherent EM radiation of whatever frequency -- thus you'll hear "IR laser," "X-ray laser," "gamma laser," etc. It would be pretty silly to insist on a separate word for each frequency band.

      • LASER is no longer capitalized? Since when? I realize we tend to use Internet English (one rule of grammar: "fuck it") but when did we start activelt discouraging the use of CAPS LOCK?

        • by Surt (22457)

          LASER is no longer capitalized? Since when? I realize we tend to use Internet English (one rule of grammar: "fuck it") but when did we start activelt discouraging the use of CAPS LOCK?

          SINCE WE HAD TO GET PEOPLE TO STOP SHOUTING!

          • I USE CAPS LOCK AT WORK FOR DRAFTING.

            No, seriously, I do have it on most of the time at work, but that's because it's for work. I'm not usually ready TO UNLEASH THE FURY.

        • by hedwards (940851)
          Laser hasn't been capitalized in a really long time. Capitalization only applies when it's an acronym and abbreviations, laser on the other hand is a word in its own right.
          • by rcw-home (122017)

            Capitalization only applies when it's an acronym and abbreviations, laser on the other hand is a word in its own right

            Light Amplification by Stimulated Emission of Radiation.

            • by JDevers (83155)

              Sure, it is an acronym...but the minute the word itself entered common vernacular, it might MEAN L.A.S.E.R., but it is spelled laser.

            • by geogob (569250)

              The day the acronym was accepted in the English dictionary as a word, it stopped being capitalized as an acronym. The word maser has also been introduced into the English vocabulary, thus not requiring it to be treated as a acronym.

        • I'm a physicist; I work in a laser lab. I never capitalize 'laser', and I've never seen it capitalized in any contemporary publication. Frankly, explicitly capitalizing acronyms gets really annoying once they enter common usage. It just gets in the way of effective communication.
      • The waves used here are non-visible, sure, but they're shorter than microwaves, closer to what's usually called infrared.

        So we likely call them lasers because no one wants to figure out how you'd pronounce iaser?

      • by thegarbz (1787294)
        Just because people are lazy doesn't mean LASER it stops being an acronym. Even if when everyone writes it lowercase it is still wrong simply because of this fact.
        • by osu-neko (2604)

          Just because people are lazy doesn't mean LASER it stops being an acronym. Even if when everyone writes it lowercase it is still wrong simply because of this fact.

          Incorrect. When it reaches the point that everyone does it that way, it's standard usage, and doing it differently is archaic. English has no central standardization body to make authoritative rules on the language (unlike French), so in English, "standard usage" and "correct" are synonymous, regardless of historic arguments about how it might have been done differently in the past.

          • by Surt (22457)

            And even the formal standards bodies for English are in favor of laser.

          • by thegarbz (1787294)
            That's the problem isn't it, not everyone does it that way or we wouldn't be having this discussion to begin with. Most academic literature still refers to LASER as an acronym. Laymen using laser is what put it in the dictionary. I expect you'll all be crying when the computer well and truly gets renamed as the "harddrive" simply because everyone does it that way.

            Which begs the question, will a slashdot reader's head explode when he reads this very sentence because of the context of the first 3 words?
            • by careysub (976506)

              That's the problem isn't it, not everyone does it that way or we wouldn't be having this discussion to begin with. Most academic literature still refers to LASER as an acronym. Laymen using laser is what put it in the dictionary. I expect you'll all be crying when the computer well and truly gets renamed as the "harddrive" simply because everyone does it that way. Which begs the question, will a slashdot reader's head explode when he reads this very sentence because of the context of the first 3 words?

              The phrase "begs the question" was coined to describe a logical fallacy, in this case a type of circular argument in which the premise assumes the conclusion (http://en.wikipedia.org/wiki/Begging_the_question). You are using the phrase in an increasingly common, but irrelevant manner.

              I am not at all sure that you should be taken as an authority on the correct usage of English terminology.

        • by Surt (22457)

          Nope, they became right when it got formalized as a word in the dictionary:

          http://www.merriam-webster.com/dictionary/laser [merriam-webster.com]

      • I too feel that it's pointlessly pedantic to distinguish such groups. But if it isn't, why don't we just call it EMASER, where the EM stands for electromagnetic.

      • by jpmorgan (517966)

        So what you're saying is this is more of a TASER.

        I suppose the upside is that when they start using this to snoop on people, it'll confuse the fuck out of police departments.

      • by BraksDad (963908)

        ...It would be pretty silly to insist on a separate word for each frequency band.

        Especially since the frequency bands are somewhat arbitrary to nature. What is the "Visible" Spectrum? There are just a few life forms that may argue with us.

    • by Surt (22457)

      http://www.merriam-webster.com/dictionary/laser [merriam-webster.com]

        1 : a device that utilizes the natural oscillations of atoms or molecules between energy levels for generating a beam of coherent electromagnetic radiation usually in the ultraviolet, visible, or infrared regions of the spectrum
      2 : something resembling a laser beam in accuracy, speed, or intensity

      • From OED Online:

        1. Any device that is capable of emitting a very intense, narrow, parallel beam of highly monochromatic and coherent light (or other electromagnetic radiation), either continuously or in pulses, and operates by using light to stimulate the emission of more light of the same wavelength and phase by atoms or molecules that have been excited by some means. Orig. treated as the name of a particular kind of maser (optical maser) emitting visible light, laser is now the general term for all

    • by rdnetto (955205)

      M = micro
      So I guess that makes this a TASER, right?

    • by mcgrew (92797) *

      This would be "Pubic Hair amplification by Stimulation of Emitted Radiation. In short, it's a PHASER.

      "Set phasers on peep, Tom."

  • by Daniel Dvorkin (106857) * on Sunday August 08, 2010 @04:13PM (#33182728) Homepage Journal

    Um, no, I know when I'm being X-rayed. A remote sensing system that can see what I have in my pockets a mile away, without my knowledge, is highly invasive.

    Yes, yes, they mean "invasive" in the medical sense: the frequencies they're using don't penetrate inside the body. But it would be nice if they'd clarify the meaning without being so blase about it. "DHS will be able to scan anyone, anywhere, any time for anything -- what could possibly go wrong?"

    • by hedwards (940851)
      They could get sued for sexual abuse? I mean gussy it up however they like, at the end of the day this is viewing people naked without permission, or really over their objections. Were this a more rational area of discussion, we'd all be able to admit that this is sexual abuse, and it's not even grey area either.
    • by hawk (1151)

      The good news is that they can only do this with highly directional lasers--as opposed to conventional lasers, which are not directional, I suppose coming from the use of non-coherent light . . .

      Really, now. Is this a weak candidate for April 1 next year?

    • Yes, yes, they mean "invasive" in the medical sense: the frequencies they're using don't penetrate inside the body.

      That's correct: the radiation will be absorbed by the first layer of watery tissue it encounters. Like, you know, your cornea. Will your airline tickets come with a coupon for cataract surgery?

  • by Joe The Dragon (967727) on Sunday August 08, 2010 @04:14PM (#33182746)

    so it does not work with sharks?

    • Re: (Score:2, Insightful)

      by Delarth799 (1839672)
      Not yet, but those bastards keep making the technology smaller and smaller and more powerful! One day they will make it small enough to be mounted onto a shark, and at that point someone else will have cloned raptors. The sharks and raptors will grow up together and then the world will end, taken over by raptors riding sharks with laser beams, all because science couldn't stop to think about the consequences!
    • Correct. This is our chance to rebel, to have weapons the sharks cannot match, so finally be free of our masters...
    • I have been told from someone who knows better that the sharks have begun training in order to hold as much time as possible outside of water. It is a conspiracy sponsored by the Government (who do you think pays for all those military subs, and what are they doing down there?)

      .

      We have to act now and begin training ourselves in order to be able to spend as much time under water as we can.

  • by spleen_blender (949762) on Sunday August 08, 2010 @04:30PM (#33182854)
    I will not be surprised to find soon there is an inexpensive way of shielding against this.

    Then again, if you've got nothing to hide, why do you have tinfoil lined pockets, citizen?
    • That's no normal tinfoil, that's antiseptic tinfoil. It's purely for hygiene!

    • I will not be surprised to find soon there is an inexpensive way of shielding against this.

      Perhaps even a free method of dampening ones clothing to the point of interfering with the beam -I'll call it sweating!

    • by hedwards (940851)
      I predict that protective cup manufacturers will go back to making them the old fashioned way, out of metal.
  • http://www.hulu.com/watch/10322/futurama-bottle-cap [hulu.com]

    But this prolonged exposure to radiation is making me thirsty...

    .
  • by tomhudson (43916) <barbara.hudson@ ... a - h u dson.com> on Sunday August 08, 2010 @04:48PM (#33183002) Journal

    Since it won't pass through metals, quick, someone patent the tin-foil bra!

    Oops, too late, now it's in the public domain :-)

  • Aren't all lasers in the THz range? I'm pretty sure all visible light and company are in the THz range.
  • by Animats (122034) on Sunday August 08, 2010 @05:24PM (#33183210) Homepage

    Tired Magazine blows it again.

    The article from Tired [wired.co.uk] is bogus. The "remote generation of terahertz radiation" is described in this paper. [rpi.edu] They generate terahertz radiation at the target by hitting it with a big enough pulse to heat it up into a plasma. This is a classic spectroscopy technique; hit something with a big laser pulse and look at the spectra coming back.

    Nobody is going to look into pockets that way, unless they burn through first. It may be useful for analyzing toxic and hazardous materials from a distance. A possible application is something that first responders point at a spill from a distance, and it comes back with an analysis. Assuming the energy transfer can be made small enough so as not to ignite anything.

    • by Surt (22457) on Sunday August 08, 2010 @06:02PM (#33183476) Homepage Journal

      So your claim is that the TSA cares enough about passenger wellfare to not plasmify their customers? I think you underestimate their devotion to providing a comfortable, pleasant travel experience.

    • by tomhudson (43916)

      So what will happen is they think the person standing behind you is a terr'rist, so they zap you ... you're converted to plasma, and they can then look at the reflected wave to see if the terr'rist really was a terr'rist or just RMS.

      Look at the bright side - you won't have to waste any more of your life standing in line with your shoes off and smelling everyone else's stinky foot-cheeze.

    • ... if they use this system for airport screening of terrorists, it will get a guaranteed 0% false negative rate.

      Plus it will speed up the boarding queues!

    • If the initial pulse is short and intense enough there would be little risk of ignition even from a volatile material.

      If I remember this right it is a matter of pumping enough energy into a layer of material to vaporize it almost instantly, the sold=>vapor transition would cool the material by carrying away the heat of the initial pulse. As long as that pulse is really, really, really, short the total amount of heat added to the rest of the material is kept to a minimum.

      This is also how LASIK [wikipedia.org] works.
  • time to go bact to the middle ages bring out the suits of armor walking around on one of those would hide u from these lasers

  • Time to buy a wet suit, or as this is military, a full metal jacket.

    • Re: (Score:3, Informative)

      by JSBiff (87824)

      "Time to buy . . . a full metal jacket."

      Yeah, I bet having Ammo in your pockets or bags will really expedite your trip.

      • by TubeSteak (669689)

        Yeah, I bet having Ammo in your pockets or bags will really expedite your trip.

        When security lines are long, getting whisked over to special screening is a
        much quicker process than having to wait 30+ minutes for the regular screening.

        Declaring a weapon in your luggage usually ensures it will get where it's going,
        since the airport worker who misdirects that bag is going to land in some deep shit.

  • I am totally patenting the Faraday Suit(TM) when this hits the air!

  • by Mkoms (910273) on Sunday August 08, 2010 @10:22PM (#33185134)
    Hey guys, I'm one of the co-authors of that Nature Materials paper. Please let me know if you have any technical questions about the work. I'm not an expert on terahertz semiconductor lasers or their applications (I was really only involved in the surface patterning of the facet with the spoof plasmonic structures), but I'll do my best to answer any questions you might have.
  • Looks like I'd better stock up on tin foil.
    At the very least,make some figures for them to see--in the shape of 1 finger salutes.

  • less invasive, since they cannot pass through water or metal.

    So they won't work, as long as you only go outside days that it's rainy and make sure all your pockets and such are always soaking wet. Keep extra bags of water to ensure that remains the case.

  • So this would be a long range pocket snake detector...
  • by Mr2cents (323101) on Monday August 09, 2010 @06:59AM (#33187032)

    With all those perverts around, my advice to beautiful women is to keep your T-shirt wet at all times.

  • oh wait, it is a banana

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