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Toys Science

Room Temperature Semiconductor of T-Rays 110

Fallen Andy noted a Physorg story that says "Engineers and applied physicists from Harvard University have demonstrated the first room-temperature electrically-pumped semiconductor source of coherent Terahertz (THz) radiation, also known as T-rays. The breakthrough in laser technology, based upon commercially available nanotechnology, has the potential to become a standard Terahertz source to support applications ranging from security screening to chemical sensing." "What did you do at the office today, honey?" "Oh, I just demonstrated the first room-temperature electrically-pumped semiconductor source of coherent Terahertz radiation. How was your day, dear?"
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Room Temperature Semiconductor of T-Rays

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  • But wait! (Score:3, Funny)

    by Malevolyn ( 776946 ) * <signedlongint@gma[ ]com ['il.' in gap]> on Monday May 19, 2008 @11:30AM (#23463066) Homepage
    What about the powerful z-ray?
    • From Ultima VII:

      by Mempto

      Despite Felcrodan's theory of 0335, there are, indeed, rays of energy that constantly bombard Britannia. In fact, these very same rays permeate of all the known space between Britannia and the stars. Recent experiments have proven my theory that these rays, known hereafter as "Mempto Rays", are lethal to all non-living matter. In fact, Mempto rays have demonstrated their ability numerous times, once killing an entire boulder in a matter of a few hours. It is my recommendation...

    • I would be more worried about the t-rays mutating into the t-virus.

      I do have my shotgun, and hand to hand weapons ready though. I figure i can pick up a couple of assault rifles from fallen police officers.
      • Re: (Score:3, Funny)

        by mrmeval ( 662166 )
        Most departments only allow semi-auto rifles except for the el1te units. Besides you have to aim for the head and full-auto is to keep their heads down and stop massed attacks.

        Zombies don't duck. []
    • by Yvan256 ( 722131 )
      What about the infanto ray?
  • Sharks? (Score:5, Funny)

    by adpsimpson ( 956630 ) on Monday May 19, 2008 @11:30AM (#23463072)

    Does it come with a shark-head mount?

    The summary leaves me unsure.

  • Where can I buy me one of those?
  • - What did you do at the office today honey?
    - Oh, I just demonstrated the first room-temperature electrically-pumped semiconductor source of coherent Terahertz radiation.
    - What?
    - Put goggles on, pressed button, computer said "pretty coherent!", had lunch.
    - Oh.. I thought you had to be clever to be a physicist..
    - Nah, monkeys do this all the time.
    • by Goffee71 ( 628501 ) on Monday May 19, 2008 @11:53AM (#23463314) Homepage
      First - don't call us monkeys!

      Second - Dang, humans have penetrated the underground ape-lab and found our laser test rig for the grand deconfibrulatex that will return us to mastery of this planet.

      • by neomunk ( 913773 )
        You laugh, but I've been praying for a scientist coup for a long time now. The 'normies' have enacted masochistic policies for too long now as the brilliant people have sat by, apparently not paying any attention to the results, and enabled them every step of the way.

        I say the next time scientists with the Good Equipment build the next paradigm changing weapon, keep it for yourselves and demand sanity in policy. That or just threaten to strike, taking the equipment home with you (a tall order, I know) so
    • "...the goggles, they do nothing!"

  • Oblig... (Score:2, Funny)

    by nih ( 411096 )
    Please refrain from looking at laser with remaining eye
  • by Wilson_6500 ( 896824 ) on Monday May 19, 2008 @12:00PM (#23463408)
    I was trying to decide if we should facetiously call this device a "taser" or "maser" when I realized that the article appears to give two different wavelength ranges for the device. The image caption seems to state that a 5-Thz wave corresponds to a 50 micrometer wavelength, whereas the article itself indicates that these lasers operate in the 3-30 nanometer wavelength range. Methinks someone used the angstrom symbol incorrectly, since 50 um * 5 Thz is about equal to the speed of light.

    So, with that aside, we still have to decide if this thing is a maser or a taser!
    • Re: (Score:3, Funny)

      by apodyopsis ( 1048476 )
      Arg, I cannot help it....

      ...a phaser?

      for the geek factor alone, I'll gladly suffer the +5 redundant rightfully coming my way.
    • No unit goof (Score:4, Informative)

      by supergumby ( 141149 ) on Monday May 19, 2008 @12:49PM (#23464044)
      The units and quantities used in the article are correct. Two lasers, with wavelength in the range of 3 to 30 nanometers, shine into a magic box. Out of the magic box comes light with a wavelength which is the difference of the two input lasers. The magic box is a material with a nonlinear response to electromagnetic waves, such as gallium arsenide.
      • by JustOK ( 667959 )
        All the more reason for space exploration. I've heard you can get arsenide from Uranus.
      • Re: (Score:2, Informative)

        by vsny ( 1213632 )
        The units are *not* correct. The article is referring to THz wavelenghts in general (30-300um's) not the "two lasers". 3-30nm would be X-rays and GaAs is not creating X-rays. In fact there is not two lasers at all, that is not how a QCL works. The blurb is not correct. You need frequency mixing to actually measure THz waves, but you don't use frequency mixing to get THz lasing in GaAs QCLs.
      • by grrrl ( 110084 )
        No, they aren't. It should read 30 - 300 um, which is the correct units quoted in the first line of the actual paper which I just dl'd from APL.
    • Well ... Taser [] is already taken...=P
    • by mckorr ( 1274964 )
      Maser and Taser are already taken. One by microwave lasers (lasers with light in the microwave bands), the other by the Texas police. They're a bit taze happy here in Texas :)
    • by grrrl ( 110084 )
      Yep you're correct, especially since their angstrom has a lowercase a!

      In fact the summary is rather fluffy, I'll wait to read the APL :)
      • by grrrl ( 110084 )
        Oh, the APL is out already - and yes the first line reads "The terahertz THz spectral range = 30 - 300 um has long been devoid of electrically pumped room temperature RT semiconductor source." (another great example of APL editing - should read devoid of _a_ source, or devoid of sources).
    • by AdamHaun ( 43173 )
      How about a teaser (T-ser)?

  • by Ferzerp ( 83619 ) on Monday May 19, 2008 @12:01PM (#23463428)
    That is what I read the title as. I had a weird symphony pictured in my head.
  • Next they will be selling X-Ray glasses made with this to kids with ads in comic books...
    • Next they will be selling X-Ray glasses made with this to kids with ads in comic books...
      You haven't read a comic book recently; they're all used car classifieds and personal ads.
  • Well I attempted to RTFA but it was waaay over my head.

    So I'll summerize some simple questions and hope there are some kindly physicists who can answer...

    1. will this help me see through girls clothing? (vaporising them and providing a 1ns window of "no clothing" does not count)

    2. does this provide any new interesting military technology with "cool!" factor?

    3. can T-rays diagnose all illnesses and promote world peace?

    4. is this anything like those airport sensors? is the world going to becom
    • 1. Yes, also their skin.
      2. T Rays are low energy, so not much profit in trying to kill someone with them. A nice rock would work better.
      3. Yes and no. They're better than X-rays for some diagnostics, but, as always, more knowledge = less peace.
      4. Yes. Except they don't see through clothes (those already exist) they look through clothes and skin. They also are more effective at spotting explosives, etc, due to peculiarities in their composition.
      5. This has always been the case.
      • by Gilmoure ( 18428 )
        Check out the subcutaneous fat on that babe! Hubba-hubba!
      • Re: (Score:3, Informative)

        by dietlein ( 191439 )

        1. Yes, also their skin.

        No, not their skin. Kindt & Schmuttenmaer (1996). 1 cm of water attenuates frequencies above 100 GHz by several hundred dB.

        3. Yes and no. They're better than X-rays for some diagnostics, but, as always, more knowledge = less peace.

        X-rays and terahertz radiation are not really competitors in the medical field, due to the fact that terahertz radiation is attenuated greatly by water, and we're mostly water. You can detect some skin conditions with it, but only those in the

        • by kesuki ( 321456 )
          i recall something about the airport usage of t-rays (and yes some airports use t-ray scanners to look for weapons, they don't scan everyone though, because the equipment was ver expensive until this new innovation.)

          I recall that the designers of 't-ray' devices had to patch their devices to 'blur' private regions, because people were getting upset that you 'could see too much detail' with the first t-ray scanners...

          making t-ray scanners 'cheaper' to build and operate will increase their use in airport sec
  • Shouldn't they be focusing on ocean temperature?
  • by hyades1 ( 1149581 ) <> on Monday May 19, 2008 @12:09PM (#23463522)

    I know there are lots more applications for this, but what the health care system could really use right now is cheaper imaging technology. I'd love to see a similar breakthrough that reduced the cost of an MRI machine to about five grand.

    • by jd ( 1658 ) <> on Monday May 19, 2008 @12:27PM (#23463774) Homepage Journal
      With the evolution of very low power, high resolution MRI systems, that's entirely possible. Highly sensitive sensors are generally cheaper than 2.5T (and would be a LOT cheaper than 9.2T) magnets and accompanying shielding. On the other hand, any new field is going to take time to move from early uses to mainstream, and getting sensors to the limits of existing MRI technology is going to take a whole lot longer. (It's one thing to demonstrate basic imaging - which is quite good enough for many purposes. It's quite another to get to the point of imaging down to the level of individual neurons. I'm guessing the 12T magnets used in animal experiments provide far more detail yet.)
      • It's not just the amount of field, it's the precision as well. One of the reasons why MRI is so clunky is that you have the main coil and then shim, tesseral, etc. coils to help "fine tune" the fields. Not to mention that the patients load the coils as well.
    • I know there are lots more applications for this, but what the health care system could really use right now is cheaper imaging technology. I'd love to see a similar breakthrough that reduced the cost of an MRI machine to about five grand.

      The only problem is, the cheaper the imaging, the more often it will be used.

      And the more often it is used, the more completely benign stuff you'll find.
      That means more follow ups, biopsies, consultations with experts, etc.
      And all that has a very real possibility of raising the costs of health care.

      So when you calculate the benefits, you have to calculate the cost of all the useless testing will happen and subtract that out.

      • So when you calculate the benefits, you have to calculate the cost of all the useless testing will happen and subtract that out.

        What does it cost to move to a country with nationalized medicine, anyway?

        • The last estimates I saw that made a serious attempt to do an apples-to-apples comparison indicated that the Canadian system delivers roughly twice the health care dollars to the sharp end (doctors, nurses, equipment and supplies, etc.) as the American model.

          That doesn't tell the whole story by any means, but it seems to indicate that the insurance companies which infest the American system are feeding very, very well.

          I don't know what the "start up" cost or "changeover" cost might be. Canada made the

      • by bitrex ( 859228 )
        I think it's unlikely that the price of scans will come down anytime soon, given that for many hospitals MRIs are a major cash cow. A modern scanner costs the hospital around $4 million, plus around a million a year for related salaries and maintenance. If they're doing an average of 15 scans per day (any major hospital with a scanner hits that number easily) and billing insurers an average of $2000 per scan (which from my experience is on the low end, my last MRI cost my insurance company $2900), they'r
  • by Speare ( 84249 ) on Monday May 19, 2008 @12:13PM (#23463572) Homepage Journal
    The blurb has a lot of jargon but no reference as to what uses T-rays are likely to be put. T-rays applications [] They're likely to help with certain cancer scans within the body, but these are also the basis for new "scan 'em naked at fifty paces" airport security cameras. I'm not sure I'm too excited about advancement in this technology just at the moment. Yeah, yeah, scanners don't scan people, overzealous control-freak post-democratic regimes scan people. But you get my drift.
    • Health Care, Smealth Care! We need to learn how to focus these beams into 50 shot clips for WWII pistols that are modified into DL-44 blaster pistol.
    • Re: (Score:3, Interesting)

      In addition to the applications you mentioned (medicine and security), a more mundane application is in manufacturing and quality control. For instance, with these scanners you can automate the quality and consistency checks on many manufactured goods, including foods. For instance, the scans could visualize the internal dispersion of nuts in a candy bar, or the consistency of bread. It could also be very useful for detecting anomalous matter in food (e.g. pick out metal or a band-aid that accidentally foun
    • T-Rays are better for this than the current "scan 'em naked" scanners, because they can be tuned to look for only weapons/bombs/whatever.

      From WP: Terahertz radiation can penetrate fabrics and plastics, so it can be used in surveillance, such as security screening, to uncover concealed weapons on a person, remotely. This is of particular interest because many materials of interest, such as plastic explosives, have unique spectral "fingerprints" in the terahertz range. This offers the possibility to combine s
  • by Animats ( 122034 ) on Monday May 19, 2008 @12:17PM (#23463626) Homepage

    First, here's the real paper. [] Actually, this is the previous paper, where they got operation at 177K, but not quite room temperature. (Don't link to Physorg; they just collect press releases, add ads, and delete the citations.)

    Terahertz waves are interesting. At one time, that was an inaccessible portion of the spectrum, above radio but below infrared. Now it's understood that it's a region in which both RF and optical techniques can work. At that frequency, propagation is line of sight, although diffuse systems, as with diffuse IR, are possible. Applications are still a ways off, but there's probably something useful to do with this stuff.

    Incidentally, "radio", by international agreement, ends at 3THz. Beyond that, it's "light" for regulatory purposes. In the US, FCC regulations (for RF) end at 3THz, and DHS regulations (as for lasers) begin.

  • by Reality Master 201 ( 578873 ) on Monday May 19, 2008 @12:18PM (#23463650) Journal
    T-ray imaging systems are what are being proposed to scan people in airports and other secure places; you can get images under a person's clothing, so you can actually see what they might have concealed.

    Check out the wikipedia page: []
    • Re: (Score:3, Interesting)

      by jeffmeden ( 135043 )
      So riddle me this: Why are Terahertz waves limited to "between 300 gigahertz (3x1011 Hz) and 3 terahertz (3x1012 Hz)" according to the article? Wouldn't it make sense for the scale to start somewhere around 1 THz and run to about 999 THz, where it would then run into Petahertz? Just curious, TIA!
    • by Der PC ( 1026194 )
      So, basically it's your standard peeping tom camera ?

      Now I can't wait until all those T-ray porn sites start appearing :P
  • Oh, I just demonstrated the first room-temperature electrically-pumped semiconductor source of coherent Terahertz radiation. How was your day dear?

    "Well, I isolated a nucleotide today..."


    • by TheSync ( 5291 ) *
      Oh yeah, I replicated thousands of strands of DNA today, just in the tip of my little finger!
  • by Doc Ruby ( 173196 ) on Monday May 19, 2008 @02:23PM (#23465134) Homepage Journal
    This THz frequency laser was made by building cheap and efficient IR lasers differing from each other by only a tiny wavelength difference, then using them to excite the active lasing material at their "beat frequency". That technique might be usable to generate ever-higher frequency lasers.

    For example, what about using two pairs of IR lasers, each pair resonating at a slightly different beat frequency? In fact a single "reference" IR laser could be split into two sources, with two different other sources each supplying their different frequencies into a THz laser of slightly different frequency. Then use those THz sources into an semiconductor active region which resonates at the beat frequency between the THz sources.

    That higher frequency result could be used as one of yet another pair, generating an even higher beat frequency. And since these steps up are made from thin film deposition, they could have such a hierarchical structure all contained in a very tiny device. Perhaps in a device at a scale that offers extremely high frequency lasers, manufactured and operating cheaply, without extra HW to maintain a useful beam.

    Perhaps a beam that could offer networks petabyte datarates. And perhaps, if the optical resonance junctions can be modulated by other photons, actual logic executing quickly, at low power.
    • by znerk ( 1162519 )
      Interesting concept. Perhaps this could be used in computing to increase the available cpu speed, without necessarily having to invest in further silicon research? We're talking orders of magnitudes higher frequency than current cpus, yes?

      This is purely theoretical, and I actually have no idea what I'm talking about.
      • It all depends on whether the engineers can make an all-optical computer. But it will all require further silicon research, as did this THz source device.
    • It makes the mind spin how quickly comcast would whip out the AUP on that connection.
  • Don't forget the F-Ray []
  • I read "Room Temperature Semiconductor of T-Rays" and thought "how can they create AC so high in frequency"?
  • Twinkle, twinkle, little bat
    How I wonder what you're at
    Up above the world you fly
    Like a T-ray in the sky.
    -- The Mad Hatter
  • I can call my self Tee Man! Wearing My Tee-Shirt, I shall fight for truth, justice, and the almighty Buck! In my secret identity as Mr. (&*%^)$(^$)

    Ow - quit hitting me Mr. T - I would never have gone there!


Genius is ten percent inspiration and fifty percent capital gains.