Terahertz Imaging:Another Way to See Through Walls 145
311Stylee writes: "Wow. I've never even heard of this before, but it looks genuine with a writeup on MSNBC and Space.com . Existing technology is used to measure sea temperatures through clouds via satellite, but newer cameras could be used in a huge array of applications because of their ability to see through walls, clothing, smoke and clouds. Google gets 546 hits on T-rays, inlcuding one from AT+T Bell Labs."
Qinteq (Score:4, Informative)
Following the election of Labour to power in 1997 the new government decided that the end of the cold war meant that this operation should make its own way in the commericial world. It's still government owned, at present, but will be sold off to the private sector at some time.
In effect these are the guys that gave the world radar and much else besides, So they mean business!
Half IR, Half MW (Score:5, Informative)
The image of a slice of bacon shows different levels of T-ray transparency for lean and fatty areas. Since fat absorbs almost no T-rays, it looks white; meat absorbs roughly 25 times as many T-rays, so it looks dark.
Many compounds changed the T-rays in characteristic ways, due to absorption or reflection. Molecules and chemical compounds, particularly in the gas phase, showed strong absorption lines that can serve as "fingerprints" of the molecules. Metals and other materials with high electrical conductivity were completely opaque to terahertz radiation.
The T-ray imaging technique is notable in that it can distinguish between different chemical compositions inside a material even when the object looks uniform in visible light. Also, most plastics are transparent to T-rays, so it can "see" inside plastic packaging.
I believe they use pulses to illuminate the targets, just so that you don't cook them
Re:Beware Sony Owners Instead... (Score:1, Informative)
Not quite the case. The camcorder doesn't emit infrared light, it just receives them that are emitted from the target, or anything with heat.
Re:Beware Sony Owners Instead... (Score:0, Informative)
I already get my kicks from watching the infrared led of the remote control with it, no need to see women naked.
Re:its 7 years old? (Score:3, Informative)
Because you'd need a cryogenically cooled detector and even wierder detector materials than you have to use for thermal IR.
A camera that detects sub-millimetre waves (the proper name for THz-range EM) is even more of a pain to build than one of the good, expensive thermal IR cameras, so unless you have an application where a thermal IR camera or X-ray system or low-power impulse radar system won't work, you aren't going to sell any.
This market is apparently small enough that nobody's mass-produced sub-millimetre range imaging systems commercially yet.
Very good article on T-wave imaging... (Score:2, Informative)
"Recent Advances in Terahertz Imaging", Mittleman et al [nec.com]
No, 540 nm (Score:3, Informative)
That is, 550e15 hz. Light is around 550 petahertz.
Re:Is this passive or active? (Score:3, Informative)
Re:No, 540 nm (Score:3, Informative)
Erm, but 540 nm = 540e-9 m = 5.4e-7 m, not 5.4e-10m. So, the frequency of 540 nm wavelength light is about 3e8/5.4e-7 = 5.6e14 Hz = 560 THz.
This is roughly in the middle of visible light (400 to 700 nanometers [nasa.gov]) so light is indeed about 550 THz.
The article's talking about stuff with a frequency down about 1 THz, though, rather than hundreds of THz (which puts you up near a petahertz).