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Using the Terahertz Spectrum for Wireless Communication

CowboyNeal posted more than 7 years ago | from the kicking-it-up-a-notch dept.

Wireless Networking 134

holy_calamity writes "A first step to allowing wireless data transfer over a currently unused part of the electromagnetic spectrum is reported in New Scientist. Terahertz radiation exists between radio and infrared. A new filter created at the University of Utah can filter out particular frequencies, a prerequisite for using it for data. The abstract of the paper in the journal Nature is freely available."

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Coming next... (-1, Offtopic)

Anonymous Coward | more than 7 years ago | (#18538797)

Optical wireless transmission.

(Yeah yeah, it already exists...)

Re:Coming next... (-1, Troll)

Anonymous Coward | more than 7 years ago | (#18538967)

Your HR Department rejects privacy and makes you sodomize the future for gangrene shit sacks.

Re:Coming next... (1)

flydpnkrtn (114575) | more than 7 years ago | (#18541391)

Yea great job on the informative side of that post there guy...

For those that don't know about it (I didn't know about it until a couple of weeks ago:
"Free Space Optics (FSO) is a line-of-sight wireless technology, which enables secure, high speed bandwidth connections using optical laser communication"

http://en.wikipedia.org/wiki/Free-space_optical_co mmunication [wikipedia.org]

It might just take a while (1, Redundant)

NixieBunny (859050) | more than 7 years ago | (#18538811)

I work on radiotelescopes that work at several hundreds of gigahertz, and the technology used there is rather exotic. There is also the slight problem of water absorption of the signal - our telescope at 10,500 ft (3200m) altitude has trouble getting a clear shot to space due to the atmosphere, so communication would have to be rather short-haul as in LAN.

Re:It might just take a while (5, Informative)

Anonymous Coward | more than 7 years ago | (#18538877)

...so communication would have to be rather short-haul as in LAN.

Perhaps TFA should have mentioned that.
 
Wait...

Re:It might just take a while (4, Funny)

NixieBunny (859050) | more than 7 years ago | (#18539007)

Are you kidding? you can't do first post if you RTFA!

Re:It might just take a while (0)

Anonymous Coward | more than 7 years ago | (#18539161)

Sure you can, if you're a subscriber. First post becomes as easy as checking the Firehose for when the article will go live.

Re:It might just take a while (1)

alphamugwump (918799) | more than 7 years ago | (#18540823)

Except everyone has firehose now, so you don't need to subscribe.

Re:It might just take a while (1, Insightful)

FMota91 (1050752) | more than 7 years ago | (#18538883)

Well, if Internet speeds keep getting better (which I'm sure they will), this could be used to make a faster Wi-Fi router. It shouldn't be too difficult in a few years. Amirite?

Admittedly, I don't know if I am.

Re:It might just take a while (0)

Anonymous Coward | more than 7 years ago | (#18538907)

I work on radiotelescopes that work at several hundreds of gigahertz, and the technology used there is rather exotic.

Sounds like NRAO-ALMA. If so, congrats, sounds like you guys are making great progress bringing the antennas online!

Re:It might just take a while (5, Funny)

psaunders (1069392) | more than 7 years ago | (#18539075)

Sounds like NRAO-ALMA.
*sigh* It irks me whenever someone posts an obscure acronym without expanding it. Seriously, it's just rude.

For the uninitiated, that is Nothing Really Amazing in Outerspace - Alien Life My Ass.

Re:It might just take a while (5, Informative)

DarkAxi0m (928088) | more than 7 years ago | (#18539495)

or... it could be for Atacama Large Millimeter/submillimeter Array - National Radio Astronomy Observatory :P

http://www.alma.nrao.edu/ [nrao.edu]

Google can be your friend too.. .

Re:It might just take a while (2, Insightful)

DarkAxi0m (928088) | more than 7 years ago | (#18539533)

Ooo my bad, looks like Google was lying to me so would be his friend.

guess i should read things before i reach for the Ctrl-C Ctrl-V

Re:It might just take a while (4, Insightful)

evilviper (135110) | more than 7 years ago | (#18538961)

There is also the slight problem of water absorption of the signal [...] so communication would have to be rather short-haul as in LAN.

Which is EXACTLY what TFA said...

But hey, what do I know, your post is a +5, so it must be somehow insightful, not 100% redundant.

Re:It might just take a while (1)

Starburnt (860851) | more than 7 years ago | (#18539125)

Perhaps TFA should have mentioned that.

Wait...
100% redundant what?

Re:It might just take a while (5, Funny)

Exocrist (770370) | more than 7 years ago | (#18539773)

All the better if he's dead on, that just saves the rest of us from having to RTFA!

Re:It might just take a while (1)

cyphercell (843398) | more than 7 years ago | (#18539091)

Ok so this would only be effective in a LAN type of situation but just as a question, wouldn't this free up some frequencies in the long run? Also does anyone have any idea on the possible ranges for point to point vs point to multi point? I'm thinking if the cost of these things goes down (a lot) and a point to point connection can get out to about a mile then point to multi point ought to cover a block, then we may have a future with these things on top of telephone poles. The distance for wimax is typically 7.5 to 1 with point to point covering the most distance.

Re:It might just take a while (1)

Profane MuthaFucka (574406) | more than 7 years ago | (#18539259)

LAN? Fuck, I'd be happy if I had terahertz communication two inches from my CPU to my memory. And terahertz memory. And a terahertz CPU.

ATTN: Windows/Linux refugees! (-1, Troll)

Anonymous Coward | more than 7 years ago | (#18539369)

Still looking for the "maximize" button when your Mac has "zoom" instead? Take the hint, switcheurs: If you can't deal with multiple windows at once, GTFO of our platform. The Mac wasn't designed for one-track minds.

So, when will this be mismanaged by the Government (2, Funny)

Kid Zero (4866) | more than 7 years ago | (#18538813)

10 years? Anyone?

Re:So, when will this be mismanaged by the Governm (-1, Troll)

Anonymous Coward | more than 7 years ago | (#18539241)

10 years? Anyone?
Hey, did you see the part where I farted?

Nikola Tesla springs to mind (1)

mrbluze (1034940) | more than 7 years ago | (#18539499)

Didn't Nikola Tesla study/invent devices which work in this frequency spectrum?

I know that not all of his inventions were made public and that much of his writing was confiscated upon his death, but does anyone have any leads on this?

Re:Nikola Tesla springs to mind (0)

Anonymous Coward | more than 7 years ago | (#18540703)

No, Tesla didn't, at least not intentionally. However, since he used spark gaps a lot, there must had been some sprinkling over that part of spectrum too.

Geek into English. (1, Interesting)

Anonymous Coward | more than 7 years ago | (#18538825)

"Resonantly enhanced light transmission through periodic subwavelength aperture arrays perforated in metallic films1 has generated significant interest because of potential applications in near-field microscopy, photolithography, displays, and thermal emission2. The enhanced transmission was originally explained by a mechanism where surface plasmon polaritons (collective electronic excitations in the metal surface) mediate light transmission through the grating1, 3. In this picture, structural periodicity is perceived to be crucial in forming the transmission resonances. Here we demonstrate experimentally that, in contrast to the conventional view, sharp transmission resonances can be obtained from aperiodic aperture arrays. Terahertz transmission resonances are observed from several arrays in metallic films that exhibit unusual local n-fold rotational symmetries, where n = 10, 12, 18, 40 and 120. This is accomplished by using quasicrystals with long-range order, as well as a new type of 'quasicrystal approximates' in which the long-range order is somewhat relaxed. We find that strong transmission resonances also form in these aperiodic structures, at frequencies that closely match the discrete Fourier transform vectors in the aperture array structure factor. The shape of these resonances arises from Fano interference4 of the discrete resonances and the non-resonant transmission band continuum related to the individual holes5. Our approach expands potential design parameters for aperture arrays that are aperiodic but contain discrete Fourier transform vectors, and opens new avenues for optoelectronic devices."

Alright, how many here can translate that into english?

Re:Geek into English. (5, Informative)

rhythmx (744978) | more than 7 years ago | (#18538925)

Basically it says that putting the holes in a fractal pattern give much better results than holes in more 'normal' pattern. The rest is Calculus explaining how they can generate patterns that are really good at transmitting a certain frequency.

Sounds really interesting. I wonder if any of this applies to antenna design at average RF.

Re:Geek into English. (2, Funny)

Anonymous Coward | more than 7 years ago | (#18539277)

This is trivial. At Starfleet Academy, surface plasmon polaritons and Fano interference in quasicrystals were on our freshman exams in the first week. Even WESLEY got it right, and he was the dumbest one in our class. Well, except for that guy, George Bush VIII. I don't know how he got in, except his father was like the king of some country named Texas or something. All he ever did was exotic drugs, until the day he blew his testicles off in chem lab. Thank goodness for modern transplant technology.

Re:Geek into English. (0, Offtopic)

cyphercell (843398) | more than 7 years ago | (#18539853)

Thank goodness for modern transplant technology.

What are you talking about? Now there will be a George Bush IX!

Why not... (0)

Anonymous Coward | more than 7 years ago | (#18538833)

Why use Terahertz when theres Petahertz?

Re:Why not... (0)

Anonymous Coward | more than 7 years ago | (#18539417)

It's all about the Petahertz baby.

Re:Why not... (2, Funny)

Greylin (72313) | more than 7 years ago | (#18539513)

oh no.. not petahertz... then we'll have those animal rights crazies demanding we let it go..

Re:Why not... (0)

Anonymous Coward | more than 7 years ago | (#18541089)

Because Petahertz is UV-radiation and since most materials are absorbing UV-radiation (by electron excitement) it is quite useless for WLANs.

HTH
HAND

Hmm, (1)

Verte (1053342) | more than 7 years ago | (#18538851)

We normally call those frequencies microwave. Microwave transmission is nothing new?

Re:Hmm, (2, Informative)

evwah (954864) | more than 7 years ago | (#18538913)

micrwave frequencies are usually considered to be the upper end of the radio frequency spectrum... the former being about 1G-300GHz, and the later covering 3Hz-300GHz.

Re:Hmm, (4, Informative)

NixieBunny (859050) | more than 7 years ago | (#18538951)

The microwave spectrum really ends at about 30 GHz, with the frequencies from 30G-300GHz called millimeter wave, and those from 300 GHz up called submillimeter. Terahertz technology is quite in its infancy. There was a terahertz conference last week, so the office I work in was pretty well cleared out. (I work on spectrometers that use what we consider low frequencies, The other thing about terahertz waves is that they behave quasi-optically, being focused by teflon lenses and blocked by cardboard. So it's not a radio band that one would use for cellphones.

Re:Hmm, (3, Funny)

Pink Tinkletini (978889) | more than 7 years ago | (#18539061)

...)

Ahhh, much better.

Re:Hmm, (4, Funny)

Kenshin (43036) | more than 7 years ago | (#18539133)

The other thing about terahertz waves is that they behave quasi-optically, being focused by teflon lenses and blocked by cardboard.

So we can finally ditch the tin-foil hats for cardboard hats? About time!

Re:Hmm, (1)

NixieBunny (859050) | more than 7 years ago | (#18539291)

Cardboard's fine. Just don't assume that your styrofoam hat will block the goverment's secret terahertz ray. Where I work, they use styrofoam for dewar windows!

Re:Hmm, (1)

Whiteox (919863) | more than 7 years ago | (#18540741)

Wax is the way to go!
It blocks everything! But don't go out in the hot sun.....

Re:Hmm, (1)

Starburnt (860851) | more than 7 years ago | (#18539023)

It's actually closer to the far-infrared, but one of the interesting things about the technology is that it bridges a gap in the electromagnetic spectrum between regions traditionally thought to be completely different - electronics and antennas at low frequencies and optics at high frequencies. It's only recently that the technology has opened up the region, so it isn't entirely obvious what to call the radiation.

Re:Hmm, (1)

cyphercell (843398) | more than 7 years ago | (#18539197)

How about "infrared waves", "red shifted microwaves", or the most marketable "redwave wireless".

Re:Hmm, (1)

Starburnt (860851) | more than 7 years ago | (#18539233)

Correction: "Blue-shifted microwaves"

Re:Hmm, (1)

cyphercell (843398) | more than 7 years ago | (#18539301)

thanks, I would still prefer "bluewave wireless" actually I think that sounds better than "redwave".

Re:Hmm, (1)

flyingfsck (986395) | more than 7 years ago | (#18539411)

Is 'RiFi' trademarked yet?

Re:Hmm, (1)

grcumb (781340) | more than 7 years ago | (#18540061)

Is 'RiFi' trademarked yet?

Somehow I don't think it would work in Japan or China.... Besides, you're missing the obvious one:

TERA-fi, dude!

Re:Hmm, (1)

pipatron (966506) | more than 7 years ago | (#18541035)

Let's improve that even further!

TERA-fi(c)

Like, terrific traffic!

Re:Hmm, (0)

Anonymous Coward | more than 7 years ago | (#18539467)

the most marketable "redwave wireless".

That's "Rd-ray wireless (tm)"

Re:Hmm, (3, Insightful)

cyphercell (843398) | more than 7 years ago | (#18539655)

Actually, screw names, I'm going to the patent office!

Patents!!! [slashdot.org]

P.S. - Mod me insightful.

Re:Hmm, (1)

Verte (1053342) | more than 7 years ago | (#18540295)

Well, I find the filter technique they use very very interesting. But different materials are more or less opaque and reflective to different frequencies, and since radio waves permeate just about everything fairly well, but scatter better [are less directional] because of the longer wavelength. So it'd make sense that the physics you get from these frequencies are ok scattering but more materials appear opaque. TFA was pretty good, I pretty much just responded to the slashdot article :P but yeah, physics of THz-frequency electromagnetic radiation doesn't feel that surprising somehow.

ridiculously expensive (5, Informative)

evwah (954864) | more than 7 years ago | (#18538865)

I regularly work with equipment that produces signals up to 50 GHz and let me tell you... components get much higher in cost the higher in frequency they go. a 3 foot 40GHz cable can cost hundreds of dollars and a 100GHz connector can cost a thousand dollars or more on its own. I imagine that producing and transmitting signals in the terahertz range is not economically viable for most companies.

Integration ... (0)

Anonymous Coward | more than 7 years ago | (#18538941)

Integrated circuits are cheap. We aren't talking about putting watts of energy into the ether here.

Re:ridiculously expensive (4, Funny)

markov_chain (202465) | more than 7 years ago | (#18538955)

Pshaw, that's nothing. I work with high end audio equipment, and let me tell you, a Hi-Fi 3 foot cable can easily cost several thousand dollars. The 40GHz cable would never be enough, as some people can still hear frequencies in that range.

Re:ridiculously expensive (1, Funny)

Harmonious Botch (921977) | more than 7 years ago | (#18538987)

As I recall, people's hearing tops out at about 25 KILOhertz

Re:ridiculously expensive (1)

spiracle (559763) | more than 7 years ago | (#18539043)

mod parent -1 "no sense of humor"

Re:ridiculously expensive (4, Funny)

sr180 (700526) | more than 7 years ago | (#18539181)

I see that his joke was above your head by 39.975 MHz or so.

Re:ridiculously expensive (1)

truckaxle (883149) | more than 7 years ago | (#18539395)

That audible wroooshing sound you hear is the joke going over your head :)

Re:ridiculously expensive (4, Funny)

Profane MuthaFucka (574406) | more than 7 years ago | (#18539539)

Are you talking about compact discs? because you can hear vinyl way higher than that.

Re:ridiculously expensive (1)

simm1701 (835424) | more than 7 years ago | (#18539881)

Most people use their Hi-Fi to listen to music

Audiophiles use their music to listen to their stereo :)

Re:ridiculously expensive (2, Informative)

John Miles (108215) | more than 7 years ago | (#18539003)

I regularly work with equipment that produces signals up to 50 GHz and let me tell you... components get much higher in cost the higher in frequency they go.

Depends on how precise you want to be. Conducting and measuring signals in that region of the spectrum with low-loss gear can be tough. Generating and receiving them isn't, necessarily. Not many people realize that some of the very first wireless communications experiments were done in the 60 GHz range, two years before Marconi [nrao.edu] .

Re:ridiculously expensive (1)

cyphercell (843398) | more than 7 years ago | (#18539237)

Precision is key for distance, this stuff already doesn't carry that far.

Re:ridiculously expensive (1)

John Miles (108215) | more than 7 years ago | (#18539419)

Not to mention the regulatory hurdles associated with spark gaps...

Re:ridiculously expensive (1)

cyphercell (843398) | more than 7 years ago | (#18539449)

I'm not that smart, just a little familiar with 802.16. Are you saying that the cost of common electronics would need to go up in order to support this?

Re:ridiculously expensive (0)

Anonymous Coward | more than 7 years ago | (#18539747)

It was a joke... the article I linked to was about using spark gaps to generate millimeter waves, and spark gaps were considered obsolete almost 100 years ago due to their tendency to jam the entire RF spectrum. Sending data over spark transmissions would make an interesting classroom demonstration -- there are ways you could do it -- but no amount of money could make it commercially viable.

That being said, the original poster's point about millimeter-wave component prices being a deal-killer is not valid, either. Go back to 1980 and see what RF components rated for 2.4 and 5 GHz used to cost!

Re:ridiculously expensive (1)

cyphercell (843398) | more than 7 years ago | (#18539939)

Well I'm glad I just said I was stupid instead of reading that, I might have said something dumber. My land-line wireless phone operates in the 2.4Ghz range, costs about $35 and I can't cross the street with it. That hardly compares with the four mile NLOS you can get these days. No offense but price still seems relevant to me.

Re:ridiculously expensive (1)

cyphercell (843398) | more than 7 years ago | (#18540033)

Nevermind [interfacebus.com]

I get it now it's the connectors not the length of the cable that matters.

Re:ridiculously expensive (1, Informative)

Anonymous Coward | more than 7 years ago | (#18539017)

Terahertz signals can be generated using microwave vacuum tubes (BWOs and Gyrotrons) and transmitted through waveguides, so cables aren't really necessary. Reception might be more of an issue, although that's not something I know much about. There is or at least has been work on terahertz generation at the University of Utah as well.

Re:ridiculously expensive (1)

YU Nicks NE Way (129084) | more than 7 years ago | (#18539249)

Since TFA is all about work done on metamaterial filters for terahertz radiation done at the University of Utah, I think you can probably assume that there's still work going on there.

Re:ridiculously expensive (1)

cyphercell (843398) | more than 7 years ago | (#18539269)

At the same time won't the cost of lower frequency hardware go down a little bit with a new premium around?

Re:ridiculously expensive (2, Funny)

fahrbot-bot (874524) | more than 7 years ago | (#18539887)

...a 3 foot 40GHz cable can cost hundreds of dollars and a 100GHz connector can cost a thousand dollars or more on its own...

So, CAT-5e is out?

Re:ridiculously expensive (4, Funny)

Erandir (578490) | more than 7 years ago | (#18540091)

I dunno, apparently many companies are already broadcasting in the 450-750 terahertz range, using something called a "light bulb"...

Re:ridiculously expensive (2, Informative)

91degrees (207121) | more than 7 years ago | (#18541497)

A TV remote uses Terahertz frequencies. The components you need depend on what you're using it for.

Re:ridiculously expensive (1)

Creepy Crawler (680178) | more than 7 years ago | (#18541733)

But that varies its frequency upon temperature constant. There's no other way to modulate other than flashes.

The name for this part of the band. (0)

Anonymous Coward | more than 7 years ago | (#18538915)

The scientific community needs to come up with a name for this part of the band between radio and infrared. Some sort of name that symbolizes that the wavelength is small. Perhaps we can all agree that these wavelengths, shorter than radio waves, could be called "microwaves".

What do you guys think?

Re:The name for this part of the band. (1)

evwah (954864) | more than 7 years ago | (#18538933)

http://en.wikipedia.org/wiki/Terahertz_radiation [wikipedia.org]

the microwave spectrum is usually considered to end at about 300GHz.

Re:The name for this part of the band. (1)

cyphercell (843398) | more than 7 years ago | (#18539555)

It seems to me after looking around here a little bit we ought to start calling it "quantum wireless" to go with that "quantum computer" we always hear about. Not trolling, it's just the summary I get goes like this: Good for LANs, very little penetration (i.e. LOS = bad for indoors), it will suffer dearly at the hands of electromagnetic interference (again cannot survive in the house) and it will be very expensive.

What's the point? (0)

Anonymous Coward | more than 7 years ago | (#18539033)

Sure you have lots of bandwidth, but frequencies that high must have totally crap penetration. if it's truly line of sight it's totally useless indoors, and probably nearly as bad out.

Re:What's the point? (1)

cyphercell (843398) | more than 7 years ago | (#18539383)

Space maybe? (thanks I was wondering about the LOS issue)

Not strictly true (3, Informative)

femto (459605) | more than 7 years ago | (#18539045)

... a prerequisite for using it for data

It's not strictly true that you need to have bandpass filters to transmit information. There are other ways to select individual users without frequency division multiplexing. For example:

  • Do it in the time domain (ultra wideband) using narrow pulses. Each user transmits at a different time.
  • Use a spreading sequence to spread the signal so it takes up the entire band, with no need for a narrow filter (CDMA). Each user has a different sequence.
  • Use multiple antennas to do space encoding. Users are separated in space, not frequency.

The gotcha is that you need some way of sampling the band. One way is to to use a bandpass filter, mixer and slow sampler. Another is to directly sample (using RTDs???) or in the case of UWB just detect pulses. Bandpass filters are the conventional way of doing it, but not the only way.

Re:Not strictly true (2, Informative)

NixieBunny (859050) | more than 7 years ago | (#18539229)

Bandpass filters are not typically used with the astronomical receivers I'm familiar with. They use a local oscillator operating a few gigahertz above or below the interesting signal and just mix it down to microwave. The usual receiver sees the imagefrequency as well as the desired frequency, but the latest generation uses a sideband-separating mixer with hybrid couplers at RF and IF ports to allow separate reception of upper and lower sidebands. The group I work in was the first to apply such receivers to actual astronomical use.

Re:Not strictly true (1)

femto (459605) | more than 7 years ago | (#18539867)

True. My bad. I was forgetting that the filter in front of the mixer isn't so much to eliminate images due to negative frequencies (when using a complex mixer with I and Q components) as to suppress out-of-band signals that might cause overloading, the non-linearity resulting in yet more images. Make the mixer linear enough and you can mix straight down then filter and sample.

Morse Code will work... (0)

flyingfsck (986395) | more than 7 years ago | (#18539307)

Hmm, just use wideband CW with Morse Code like the old spark transmitters. That works just fine at any frequency.

Too slow (1)

iminplaya (723125) | more than 7 years ago | (#18539063)

I want gamma ray wireless.

Optical... (0)

evilviper (135110) | more than 7 years ago | (#18539127)

Once you get close to the frequency of infrared light... Why not just make the jump, and go with light instead?

They're both going to be line-of-sight anyhow, with anything that blocks light very likely also blocks THz rf.

Light, however, has the distinct advantage of being ridiculously cheap to implement... You could cheaply put 1 (or more) transceivers on every side of every device so that it never has to be reoriented to communicate in any specific direction.

IrDA isn't very fast, but only because it was only designed as a replacement for RS232 wires, not networking. Speeds could be pushed higher than anything in the UHF spectrum, as evidenced by fiber optics.

Re:Optical... (0)

Anonymous Coward | more than 7 years ago | (#18539313)

High-speed optical wireless is "hard", but so were fiber optics. I say go for it!

Re:Optical... (2, Insightful)

Short Circuit (52384) | more than 7 years ago | (#18539455)

Once you get close to the frequency of infrared light... Why not just make the jump, and go with light instead?
Perhaps because there aren't many known ways to tune the frequency of visible-spectrum EM emissions at rates which make using that part of the spectrum in that manner effective?

Terahertz research would seem to me to be a step in that direction, by bringing existing EM modulation techniques closer to that spectrum.

And, in the end, we're not going to want to stop there. We're going to eventually want to extend application of understood techniques to the UV bands and beyond.

It may not be effective for communicating in atmosphere, but it'll eventually be a great high-bandwidth solution for intercraft and interplanetary communications. The smaller you can make the parabolic dish, the easier it becomes to effectively focus the signal.

Re:Optical... (1)

evilviper (135110) | more than 7 years ago | (#18539505)

Perhaps because there aren't many known ways to tune the frequency of visible-spectrum EM emissions at rates which make using that part of the spectrum in that manner effective?

I'm not sure what point you're trying to make here. "Tuning" is absolutely not necessary. Simple off/on digital communications work at very high speeds with fiber optics in the visible light spectrum right now.

Re:Optical... (1)

Short Circuit (52384) | more than 7 years ago | (#18539627)

Simple on/off signaling is a very low grade form of amplitude modulation, and thus places limitations on the kinds and rate of signaling you can do without bleeding into neighboring frequencies.

Modulation using FM or QAM allows one to pack a lot more data into a much smaller frequency band, but they require the ability to alter the frequency of the EM radiation.

Re:Optical... (1)

evilviper (135110) | more than 7 years ago | (#18539797)

I don't believe frequency overlap is much of an issue with short-distance/line-of-sight (wireless) communications to begin with. It would have to be a very dense open space for many devices to be competing for spectrum.

Re:Optical... (1)

Short Circuit (52384) | more than 7 years ago | (#18539885)

What with the trend to add information capabilities to anything and everything, I wouldn't be surprised if, in 30 years, we had wireless networks insanely dense by today's standards.

Another thing...Digital amplitude modulation works fine for fiber because fiber has a very high signal-to-noise ratio as a medium, leading to high data integrity. Open does not. FM and QAM offer some protection against this. Listen to the radio during a thunderstorm. Switch between AM and FM, and listen to the noise on each. The AM stations are much noisier than the FM stations, which only click and pop during major bolts. The AM stations, on the other hand, pick up every bit of cloud-to-cloud static discharge.

Re:Optical... (1, Flamebait)

Max Littlemore (1001285) | more than 7 years ago | (#18539617)

Once you get close to the frequency of infrared light... Why not just make the jump, and go with light instead?

Ummmm. In case you didn't know, people have been using light for years. Ever heard of semaphore?

Re:Optical... (1)

evilviper (135110) | more than 7 years ago | (#18539835)

High-speed digital communications bear little resemblance with low-speed manual signaling.

That said, I'm not sure why you got a Flamebait mod.

Re:Optical... (1)

Max Littlemore (1001285) | more than 7 years ago | (#18539923)

That said, I'm not sure why you got a Flamebait mod.

Probably because there are no "-1 I don't get it" or "-1 That joke was really lame" options.

Re:Optical... (2, Informative)

Mad Bad Rabbit (539142) | more than 7 years ago | (#18539657)

Once you get close to the frequency of infrared light... Why not just make the jump, and go with light instead? They're both going to be line-of-sight anyhow, with anything that blocks light very likely also blocks THz rf.

Actually no; terahertz rays [wikipedia.org] can go through wood, sheetrock, masonry, etc. (but not metal or water).

Re:Optical... (1)

cyphercell (843398) | more than 7 years ago | (#18540023)

Some controversy surrounds the use of terahertz scanners for routine security checks due to the potential capability to produce detailed images of a subject's body through clothing.
X-ray vision [wikipedia.org]

That's what I'm waiting for :)

Attention Windows Clickarounds (-1, Offtopic)

Anonymous Coward | more than 7 years ago | (#18539231)

Yeah i'm talking to you. The wannabe computer programmer who thinks they are good at computers because they can click around the computer enough times and find the reboot button and 'fix' an inherently flawed windows system. You think you're cool because you can pirate photoshop but not know anything about it, get Microsoft Office for free but have the literacy of a 1st grader when writing a paper, and get a copy of Norton Anti-virus because your inherently flawed system is useless without Administrative privileges. Get a clue, you are not smart, you are just a corporate sheep for a company that will bury you if you ever tried to write any software that did anything remotely useful. You are a clickaround and all you know if your ugly gray existence that is Windows.

Want the sourcecode to windows vista?

head -n 1000000 /dev/random > Windows.com

Hmm (0)

Anonymous Coward | more than 7 years ago | (#18539987)

That terahertz filter looks a little like Penrose aperiodic tiling [wikipedia.org] .

Re:Hmm (1)

cyphercell (843398) | more than 7 years ago | (#18540067)

Could be because they're both quasicrystals [wikipedia.org] .

I am something of an expert in these matters (0)

Anonymous Coward | more than 7 years ago | (#18540113)

Nonetheless, a question: does anyone know offhand how much power these devices require?

Something in the jigawatt range, mayhaps?

It seems to be speculation (1)

kocsonya (141716) | more than 7 years ago | (#18540127)

The New Scientist article is talking about comms, but the Nature abstract actually doesn't have a single word in it with that regards. It only talks about completely different uses. From the abstract:

"Resonantly enhanced light transmission through periodic subwavelength aperture arrays perforated in metallic films has generated significant interest because of potential applications in near-field microscopy, photolithography, displays, and thermal emission."

No comms there at all.

Clueless.... (2, Informative)

j_square (320800) | more than 7 years ago | (#18540751)

Another example of how the tabloids (Nature & Science) publish things that have been known for ages... There seems to be a trend that you can get anything published there, since the peer review is done by totally clueless physicists who do not know anything about the state of the art.

The concept of making filters by cutting holes in a sheet of metal has been known for ages. Using periodic (or in this case quasiperiodic) metallic patterns is called Frequency Selective Surfaces (FSS). There are numerous books and tons of publications in IEEE transactions, etc. in this area.

I did etched FSS filters for 375 GHz around 1982, and the concept was already pubslished in books by then.

Old stuff. Too many scientists, too much money, too little brain.

Putting SETI out of business (1)

Ace905 (163071) | more than 7 years ago | (#18540809)

Watch them put together their first prototype crystal radio with their new 'filter' and find an entire cosmos of alien phone calls, television broadcasts and quasar's giving off travel-instructions to nearby ships.

Some people here have said, this is very old news and the article is the equivalent of saying, 'one day railroad lines will cover this great country of ours' -- but seriously, how many average people - like myself, are aware that we're still not using the full EM spectrum available to us. I thought we conquered radio waves in the 50s and everything since then has just been 'computing speed'. I think this is pretty interesting.

It will be cool to see what new forms of cancer and mental disease equipment broadcasting in this spectrum doesn't cause.

---
WRONG frequency! [douginadress.com]

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