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Room Temperature Semiconductor of T-Rays
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?"
Very strong,dangerous and powerful, but with teeny-tiny arms
rewriting history since 2109
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!
From reading the article, my layman's-"I'm no physicist"'s take on T-Rays:
1) They can penetrate through clothing/plastic/flesh, and most of the materials mentioned seem to be organic in nature. This gives them "X-ray"-like properties.
2) They were able to make T-Rays before in laboratories, but now they can make them more cheaply, with less power, in human-friendly settings.
3) T-Rays give off less radiation than X-rays, due to the much larger wavelength.
Quick Conclusion: We now have the potential to create an X-ray like device that could be deployed in airports and other travel hubs that could be used to monitor the public without harming the public through this observation. More benignly, they could also be used in hospitals for "persistent monitoring" of patients with tumors or internal bleeding, because they seem to have lower power requirements and risks of side-effects.
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.