terahertz
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Metamaterials used to focus Terahertz lasers, make them useful
Forget old and busted X-rays, T-rays are the future, man! It was only recently that we were discussing Terahertz lasers and their potential to see through paper, clothes, plastic, flesh, and other materials, but that discourse had to end on the sad note that nobody had managed to make them usable in a practical and economically feasible way. The major hurdle to overcome was the diffusion of Terahertz radiation -- which results in weak, unfocused lasers -- but now researchers from the universities of Harvard and Leeds seem to believe they've managed to do it. Using metamaterials to collimate T-rays into a "tightly bound, high powered beam" will, they claim, permit semiconductor lasers (i.e. the affordable kind) to perform the duties currently set aside for sophisticated machinery costing upwards of $160,000. Harvard has already filed a patent application for this innovation, and if things pan out, we might be seeing body scanners (both for medical and security purposes), manufacturing quality checks, and a bunch of other things using the extra special THz stuff to do their work.
Invisibility cloak upgraded to bend infrared light, not to mention our minds
The fabled cloak of invisibility was once considered impossible for modern science, chilling out with perpetual motion up in the clouds, but these days scientists are tilting at blurry windmills with a modicum of success several times a year. The latest advance in theory comes to us from Michigan Tech, which says it can now cloak objects in the infrared spectrum. Previous attempts using metallic metamaterials could only bend microwave radiation, the study claims, but using tiny resonators made of chalcogenide glass arranged in spokes around the object (see diagram at left) researcher Elena Semouchkina and colleagues successfully hid a simulated metal cylinder from 3.5 terahertz waves. While it's hard to say when we might see similar solutions for visible light, even a practical application of infrared cloaking could put your night vision goggles to shame, or perhaps block covert objects from being detected by those newfangled terahertz x-rays.
Terahertz radiation and metamaterials combine to form super X-Ray specs
It looks like somebody actually coughed up the extra dollar for the De Luxe model X-Ray specs in the back of Mad Magazine, then reverse-engineered 'em in the name of science. That somebody is Richard Averitt, whose team at Boston University has come up with a way to use metamaterials and terahertz transmissions to see through you. We've seen metamaterials plenty of times before, typically being used for nefarious deeds on the opposite end of the spectrum: invisibility cloaks. Here they form pixels for a digital imager that can be activated by THz radiation. If you're not familiar with THz radiation, it's a (supposedly perfectly safe) form of energy waves that pass through materials -- much like X-Rays but without all the nasty DNA-shattering effects on the way through. There's just one problem: nobody (not even this guy) has made a powerful enough THz emitter just yet, meaning we're all safely naked under our clothes for at least another few years.
Sonic 'laser' developed, makes quite an impression at 80s night
A researcher from the University of Nottingham and his Ukrainian colleague have built the world's first Saser: a device that generates a highly concentrated beam of sound waves at terahertz frequency. Not unlike the frenetic warblings of Welsh chanteuse Bonnie Tyler, when alternating layers of aluminum arsenide and gallium arsenide are exposed to an intense beam of light, photons are released, causing them to bounce back and forth between the layers. Eventually the sound waves combine into much stronger, highly concentrated sounds in which every particle is synchronized -- creating an ultra-high frequency "phonon" beam. Although practical applications for this technology have yet to be developed, it is hoped that Sasers could someday be used to probe and manipulate electronic devices at the nanoscale level, with results that include terahertz-frequency processors which would make the "computers of the future" a thousand times faster. Video after the break.[Via Gizmag]
Researchers take aim at terahertz computing
It's not everyday that researchers make some progress towards terahertz computing, but a team from the University of Utah led by Ajay Nahata appear to have done just that, with them announcing that they've "taken a first step to making circuits that can harness or guide terahertz radiation." That, they say, could allow for the development of "superfast circuits, computers and communications," and "in a minimum of 10 years," no less. The key to this latest development, it seems, is the use of some sheets of stainless steel foil perforated with tiny holes, which can be arranged in different patterns to effectively form "wires" to carry the terahertz radiation. In their tests, the researchers were able to do so at a level of 300Ghz (or 0.3 terahertz), although they admit that they still have a long way to go, saying that "all we've done is made the wires" for terahertz circuits, and adding that there still needs to be devices like switches, transistors and modulators developed at terahertz frequencies in order for anything practical to become possible.[Via TG Daily]
Mini-Z T-ray imaging device takes home the gold
We're all about giving golf claps where they're due, and a healthy round is certainly in order for Mr. Brian Schulkin. The doctoral student in physics developed a breakthrough terahertz imaging device, dubbed a T-ray, that has already demonstrated its ability to "detect cracks in space shuttle foam, image tumors in breast tissue, and spot counterfeit watermarks on paper currency." The Mini-Z marks the first time such a powerful device has become portable in nature, weighing just five pounds and taking up about as much space as your average laptop. Taking home the first Lemelson-Rensselaer Student Prize ($30,000), Schulkin explained that this device didn't pose the same health risks as typical X-rays, and unlike ultrasound, terahertz waves can provide images and spectroscopic information without contacting an object. As expected, the patent-pending technology is already up for licensing, and has already received quite a bit of fanfare and commercial interest from larger companies. So while you may never personally encounter Brian's earth-shattering invention, we're fairly sure this young lad's working days are already drawing nigh if he so chooses.[Via Physorg]
Transistors nearing the one terahertz barrier
Tossing the all-too-common "world's fastest" label on your latest gig seems to happen entirely more frequently than necessary, but researchers at the University of Illinois at Urbana-Champaign are make this claim legitimately. While we've seen those wee transistors ratchet up in speed, these gurus have shattered any previous records that may have been standing by crafting a transistor "with a frequency of 845GHz," which is "approximately 300GHz faster" that those built by "other research groups." While the terahertz barrier is arguably the "Holy Grail" of transistor speed, this leap forward doesn't leave them too far off from the ultimate goal. In addition to the pseudomorphic construction, the crew also used tinier components in order to "reduce the distance electrons have to travel, resulting in an increase of speed." Notably, the chip "only" runs at 765GHz while ticking along at room temperature, but chilling it to minus 55-degrees Celsius bumps it up to the record-holding 845GHz mark. Developers are quite pleased with the results, but as expected, aren't entirely satisfied, and seemingly can't wait to push the envelope a bit further and break their own record sometime soon.
