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Mastering Light
thyristor writes "'Researchers at MIT document the ultimate control over light: a way to shift the frequency of light beams to any desired colour, with near 100 per cent efficiency. This technology could revolutionise a range of fields, from turning heat into light, or even into prized terahertz rays - which hold great promise for medical imaging. It could also make it possible to focus a wide range of frequencies into a narrow band, make devices such as light bulbs and solar cells more efficient, and help to keep optical telecommunications networks moving.' These are probably the most exciting results in photonics in the last decade."
Will someone else shed more light into the matter???
for the next-generation laser pointers!
Should make for more efficient floyd shows..
nuff said
FLASHLIGHTS were cool?!?!?
___ Shout Central - Crushes your nuts!
So, with this, could we look at Ultraviolet radiation with the naked eye (through a converter)? That would be cool! :).
Being able to see infrared radiation would help a lot for playing hide and seek in the dark
How long until we have lightsabers?
/. had an article about lazer rifers for the U.S. Military, would they be able to actually curve the beams around objects and such?
But honestly, do they have the ability to actually shift the light, almost like a curve effect to the beam. Cause I know not too long ago
Can someone in the audience shed more light into the matter?
Playing pong with lightwaves.
"God fights on the side with the best artillery." - Napoleon, Marshal of France - speaking truth to power
...that we will soon be able to buy real, lethal Star Wars light swords, too? Then I should dust off my EVIL EMPEROR SUIT and practice the EVIL EMPEROR LAUGHTER a bit more! Muhahahahahaha...
-- Power corrupts, but PowerPoint corrupts absolutely.
Reading the article it seems that the light frequency is altered for only a short time, the time during which the shock wave passes through the crystal. So I don't think it's some magic filter where you can shine a green light in one end and get red light out the other. In the long term the number of peaks and troughs you put in at one end must equal the number seen at the other, so you can't consistently alter the frequency of a light beam in this way.
IANAP, anyone care to provide more detail than seen in the article? Will the planned demonstration of the work give results observable to the human eye?
-- Ed Avis ed@membled.com
finally I won't have to keep changing these lightbulbs all around the house. Plus I can have funky colors :D
Ok, now, can we control the "shift" from software? which a real explaination for how StarTrek does those "lets generate a xMhz pulse" sorts of things... sending hailing signals over arbitrary frequencies. (like if you had an array of these devices tuned to different freq.). Also, (boy the nerd in me loves this), it generates ideas for reception.. tuning all sorts of frequencies into a standard freq (like for SETI searches....)... wow, neat idea folks.
meh
Joannopolous was also involved in the development of the "perfect" dielectric mirror, which was mentioned here before.
If they could shift heat waves -> light waves, then absorb those with photovoltaic cells, we could harness lots of wasted energy. Almost everything generates wasted heat energy, and isn't heat energy basically the same thing as light waves, just at a different frequency?
I call it a "laser"....
The description in the article reminds me of the fictional workings of the Enterprise warp core.
"Captain, I think we can modulate the dilithium crystal resonance and redirect the warp increase to the forward sensor array!"
In other words, it sounds brilliant without actually making any sense.
Wireless electricity ?
Trolling using another account since 2005.
Does this mean we are one step closer to having full optic camo like ghost in the shell?
So, does this mean we can make ourselves invisible? If we would make a suit of frequency shifters we could make the visible light turn into radio waves, let them pass through the body, and then change them back into visible light. Of course, it would require huge amounts of energy aswell as precision, so it probablly won't happen anytime soon. Interesting thought, though.
An optical router. An incredible array of lenses and lasers and "light controllers". It would take up an entire room and be a dust free vacuum. It would be so awesome, not to mention cool looking.
The GeekNights podcast is going strong. Listen!
This would actually be pretty cool for the average DJ or night club, since traditional filters are so inefficient, and thus cause you to use higher wattage light, and more heat (and more AC to deal with it). This could make club lighting more attractive, more sophisticated and more varied.
:-)
After all, if science can't help drunk/horny/single people get laid, what good is it?
Tequila: It's not just for breakfast anymore!
MIT is a school, and thus very caught up in ego. Why can't research be disconnected from learning centers? Schools are caught up in the lie that going there makes you special. Read the damn book and you are just as well off.
-Libertarian secular transhumanist
...all those burning posts sent my way will just give me a nice tan!
Have you seen my stapler?
can x-ray glasses be far behind?
I flat panel displays will no longer need separate reg, green and blue pixels. They could just have uniform pixels which could produce light in any shade required. Should be good for higher resolution displays, greater colour depth. But might mess up things like sub pixel rendering.
http://grc.com/cleartype.htm
"Taligent is still pure vapor. Maybe they'll be the last who jumps up on Openstep... "
The researchers worked out that if a photonic crystal is designed in a certain way, incoming light can get trapped at the shock wave boundary, bouncing back and forth between the compressed part of the crystal and the uncompressed part, in a "hall of mirrors" effect.
Could this be the starting point for some sort of photonic condensator? Maybe, this could in turn be used for building a volatile photonic memory system?
That would mean a great leap in photo-electronic computer systems, since normally, a lot of the speedup from using optics in systems is lost due to slow(er) memory. But maybe the quality of the signal degrades too fast to be usable, afterall 0.1 nanosecond is hardly usable in most cases. Maybe somebody knows more about photo-electonics to figure this one out?
How does this score +5!?!!?
If you read the article you'd see that the light indeed emerges from the crystal at the new frequency. How could it make light bulbs more efficent or produce tetrahertz radiation for use in medical diagnostics if the light didn't emerge with a different frequency?
Whether the story is good or not isn't the issue. If you don't like how the system is moderated then its entirely your option to fuck off. I'm sure most here would appreciate such a wise choice on your behalf.
The approach is destructive of the crystal used for filtering the light, although they hope to be able to use sound waves in the future. Due to the distorion of the crystal lattice structure required, even sound waves may wind up breaking the crystal (remember the old memorex commercials with the singer breaking a crystal wine glass). The approach is very interesting, but there still are some serious design issues that they need to address, otherwise, it will be tough to deploy this for applications such as optical repeaters or switches.
Well, with such a frequency translator, we can all imagine all the goodies and baddies that can be made with it. One of them is a cloaking devices, efficient power sources, phase weapons...
Imagine changing harmless light from light bulbs into a focused gamma rays or worse !
I think the summary's mention of "near 100% efficiency" is misleading. It all depends on how wide your definition of the system is. Yes, technically the material itself appears to be highly efficient, but that's discounting all the energy used creating the shockwave necessary to give the material these properties.
A fascinating discovery, yes, but a miraculous way to convert energy to suit our needs it is not.
Have you seen my stapler?
set phasers to stun? forget x ray glasses, how about IR/Millimeter wave radar (or better) and other funky stuff. all you'd see with x rays are bones. what you see with millimeter wave might get you....er...nevermind. =D on with the science!
I'm confused. Are you saying that MIT researchers have developed a new "Cyrstal Light" drink mix that changes colors? What flavor is it?
I'd be curious to know the breadth of the effect (possibly limited to those wavelengths that can be captured by photonic crystals?). I mean, visible light is only a very small part of the EM spectrum. http://www.lbl.gov/MicroWorlds/ALSTool/EMSpec/EMSp ec2.html
Could this effect mean one could upshift radio waves to hard xrays? Or microwaves to gamma rays? The idea that this can be done with nearly 100% efficiency is the biggest wow-factor and seems like it should be violating the 2nd Law of Thermodynamics.
-Styopa
"These are probably the most exciting results in photonics in the last decade."
... since 1993's blue LEDs ... what exactly wonderful has happened in the field of photonics.
Wow wee. Let's see
That's right, not a shit.
Being a little more serious, though, clearly I should have paid a lot more attention in those lectures on abnormal refraction in crystals. Thanks to my lecturers for making crystallography boring all those years ago, when nowadays it's just about the most important set of technologies out.
Panurge has posted for the last time. Thanks for the positive moderations.
...shift happens!
Q: "Why do sound techs say 'check 1, 2'?"
A: "Cause if they could count any higher they'd be lighting techs."
Not much more information than in the article, but here's the abstract. This is pretty similar to Bragg scattering, which is a well known effect that uses sound waves to upshift the frequency of light. Current Bragg cells are very inefficient and are limited to small shifts in frequency. A high efficiency Bragg cell capable of shifting frequency by a large amount would be extremely interesting.
From Physical Review Letters.
Color of shock waves in photonic crystals
Evan J. Reed, Marin Soljacic, and John D. Joannopoulos
Unexpected and stunning new physical phenomena result when light interacts with a shock wave or shock-like dielectric modulation propagating through a photonic crystal. These new phenomena include the capture of light at the shock wave front and re-emission at a tunable pulse rate and carrier frequency across the bandgap, and bandwidth narrowing as opposed to the ubiquitous bandwidth broadening. To our knowledge, these effects do not occur in any other physical system and are all realizable under experimentally accessible conditions. Furthermore, their generality make them amenable to observation in a variety of time-dependent photonic crystal systems, which has significant technological implications.
Physics, Cosmology and
Intel's Pentium 5 is the coldest processor ever, and it also provides a light show as you listen to your pirat^H^H^H^H^H legal mp3s!
the light frequency is altered for only a short time
...
... metastable. :-) It doesn't matter, the point is that the wavefronts are recreated continuously, and with sound that doesn't seem all that hard.
The "short time" doesn't really matter, and furthermore looking at a "light beam" as an end-to-end continuous sine wave that you stretch and compress doesn't really help here
Photons last forever (well, until absorbed etc). Once one has escaped from the reflection zone between shockwave fronts, it doesn't wither and die, it's permanently changed to do our beckoning. The fact that its "home of origin" has since moved on isn't really of any further concern. (And notice the difference in velocities between light and shock wavefronts, ie. hare and tortoise, so from the photon's point of view the generator is pretty static.)
Complaining that the shockwave fronts are transitory is like complaining that the metastable states in lasers are, er
"The question of whether machines can think is no more interesting than [] whether submarines can swim" - Dijkstra
Having the ultimate sunglasses... have it shift Ultra-violet to a more visible frequency...
Or perhaps even infrared/heat?
Cool glasses that make you see in the dark? (military applications?)
Whee!
- The work is impressive, says materials chemist Michael Sailor at the University of California, San Diego, whose team has developed flexible, biodegradable photonic crystals. He says he now plans to test the phenomenon for himself.
Sounds like they didn't manage to make crystals that actually *last*, and are attempting to sell this bug as a feature.Who says the physical engineering guys can't learn anything from the software guys?
yes, we have no bananas
"We ought to be able to do things that have never been possible before," Joannopoulos. While this is true, its application remains to be seen. I'll wait with held breath for their publication.
On the same note, I wounder wheather this is just the begining of similar earth shattering (whell, light bending in this case) breakthroughs in other fields due to bringing ideas of two different fields together. Most optics people I know would never even consider bringing sound into the picture.
My prediction: new sight and smell techniques will revolutionze the way scientists do research by allowing for instantaneous point density determinations in complex 3-d flows. (Extremely useful!) This will happen when this advacment using sound to modify crystal properties is coupled with a device that picks up minute particle changes over a surface (smell) and correlates the two internally.
-=fshalor
there is one interesting site regarding MIT - reallife.lv
Certainly as good as most others, and it provided some good responses. What more do you want?
Does this mean my laser pointer will be able to hit the moon? :D
I've left to find myself. If you happen to see me, please, keep me there until I return.
Hmmm.
This research could point the way for automotive lighting systems that are far more efficient than today's lights but use a tiny fraction of its power.
Already, we've seen LED taillights on a number of cars such as the Nissan Skyline (as the Infiniti G35 is known in most of the world). This research could lead to LED-based automobile headlights that are just as bright as the high-intensity discharge (HID) xenon headlights found on more expensive automobiles but doesn't need the expensive power generating system HID headlights now need and uses a tiny fraction of the power needed for regular headlights. Other lighting systems such as fog lights could benefit from these new technologies, too.
This certainly sounds like an excellent advance in the field.I have been aware of interesting work with shock waves in other materials, for example, to create hydrogen metal, but it wouldn't surprise me if these claimed results were valid.
There are a couple of problems with the article and its claims, however:
I hope for the best, but remain sceptical; let's hope these new shockwave effects become easier to generate and exploit!
I also commented this story here, but I also previously posted another column on this subject. Please read it if you're interested by the photonic revolution.
It seems to me that this might finally explain why lightsabers require crystals... at least to get the cool colors.
Now we can convert those nasty IR photons back into UV photons and beam them back into space where they belong!
8-)
Tiller's Rule: Never use a word in written form that you've only heard and never read. You will end up looking foolish.
Isn't Doppler shift asymmetric on the upshift in one direction and downshift in the other, seeing as it's asymptotic at the high end approaching the speed of light? That would also explain why they can only achieve a downshift and not an upshift.
... :-)
Time to dig out my relativity primer
IAAP (I am a Physicist) and the effect is pretty simple. I think anyone should be able to understand it if it is explained properly.
"Doppler Shift" is a phenomena you are already familiar with. Consider a car honking its horn as he drives by at freeway speeds. As he approaches, the sound is heard at a higher frequency. As he passes by, the frequency shifts, and as he is leaving, the frequency is lower than normal.
Light is like sound in that it is a wave and has a frequency. Let's examine light from high to low frequencies. X-Rays are light at extremely high frequencies. Ultra-Violet light is just above the visible light range. Then we get into the rainbow - blue, then green, then red. Next is infra-red light -- light just below red in frequency. Travelling farther down, we start to reach the radio band. Below that, the frequencies are so low that it no longer is light anymore, but more like a slowly shifting magnetic or electric field.
The Doppler effect works for light as well. The problem is you or the object emanating the light has to be travelling near light speeds to see any noticeable effect. We call this "redshift" in astronomy, because stars seem to be travelling away from us, and so the light emanating from them is lower in frequency (more red). Certainly, attaining near-light-speeds is dangerous and difficult. We're not talking "bullet" fast, we are talking "cosmic ray" fast.
However, there is an oh-so-tiny Doppler shift when *any* motion is involved with light. When your friend walks towards you, the light bouncing off of him is slightly more blue. When he walks away, it is slightly more red. Good luck actually detecting this, however.
Photonic crystals have the strange property of behaving like a piece of glass at one moment, and a mirror the next, depending on how much pressure is applied where.
So, using a proper push on the crystal, it is possible to set up a travelling hall of mirrors. The light appears to be slightly shifted due to the Doppler effect to the mirror, so when it is reflected, the light is shifted, by an oh-so-tiny amount. Multiply that shift by a kazillion reflections, which is quite possible if you make the hall of mirrors very tiny (think atomic scale), and you can control light to almost any frequency, high or low, depending on how you set up the mirrors.
So, the net effect is light goes in at one frequency, and comes out the other end at another, without expending hardly any energy to get it done.
The engineering challenge is configuring the crystal so that it can withstand the forces that need to be applied, and applying the forces in a controllable way. Right now they are doing tests with bullets and crystals, because they only need to record data for the instant that the shock waves are travelling through the crystal, and they don't mind using a cheap, destructive method. In the future, they will probably use sound waves to control the crystal. But how they configure this is left to the imagination.
The applications are numerous, and some of them are listed in the article. Needless to say, if we want to use light to transmit data, the more control we have over the light, the more effective we can be in transmitting that data. Also, doctors will be happy because we can now easily exploit the Terahertz range for X-ray type applications.
The radical sect of Islam would either see you dead or "reverted" to Islam.
Thank god... now just before Zephran Cochran launches, we'll have the frequency shifting lasers we need to stop the Borg without any help.
FREE MUSIC
This is certainly an interesting result, but its heavily hyped as well.
First of all, there are many many ways to shift the frequency of light, both up and down in frequency, with both linear and nonlinear means, - from the Raman effect in optical fibers (scattering off vibrations of silica molecules) to Optical Parametric Oscillators (nonlinear wave mixing), supercontinuum generation (using a multitude of nonlinear effects to generate broad bandwidth from a single laser) to simple OEO conversion (detect your light with a photodiode and use it to drive another laser at a different wavelength. Contrary to what this article implies, these effects work at modest power levels in todays optical fibers, and many are highly efficient, and work over extremely broad bandwidths. For example, supercontinuum generation can generate light sources with bandwidth covering the entire visible, UV and IR spectrum in one source! If you want to talk about bulk optic techniques for wavelength conversion, the list is even longer.
Now think a minute about what these guys are proposing. They have to shock the crystal. Initial experiments will destroy the sample. Maybe they can refine the technique down the line to nondestructively shock the sample, maybe they can't. Certainly, infinite bandwidth won't be available, since the amount of wavelength shift will depend on the amount of shock. A single shot technique for wavelength shifting, while interesting, isn't all that useful practically.
Second, they are using a shock, so conversion of CW light is out of the question, only pulses can be converted here, or you risk a time dependent wavelength shift, as your shock dies out.
Finally, claims of a completely new physical effect seem somewhat overblown. It is an interesting idea, but Doppler shifting off acoustic shocks, and photonic crystals are well known. Marrying the two together and finding a stable regime of operation is novel, but not quite the same as discovering a new physical princple like relativity or quantum mechanics, for example.
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I need to start reading "New Scientist" magazine as "Not Science" magazine. They, like Discover, are far too focused on hype at the neglect of content.
Given one hour to live, the student replied: "I'd spend it with professor FP who can make an hour seem like a lifetime."
So we can finally have passive heatsinks with heat-powered neons while keeping CPUs cool??
Wait. This is slashdot. Wake me up when this is real life
Otherwise every single Slashdot topic gets classified based on comedy value, because making a comic quip is so much easier than a considered technical response.
A cap at Score:4 for Funny would help a lot.
this would be something of interest to many casemodders out there.. remember: don't stare to long on a overclocked computer.. you might go blind :)
- I choked on the red pill and now I'm stuck in limbo
Wohoo! Invisible vibrators!
rtt
The article mentions an interesting fact that the researchers are using bullets instead of sound shock waves. "That will, of course, destroy the crystal"... I can just imagine what goes on in that lab:
"Allrighty, George, it's your turn with the gun."
"But Bill, you know George can't hit the broad side of a barn!"
"Nonsense, my dear fellow. We need to produce some blue light soon, and that calls for a once-in-a-blue-moon event. Come on, George; ready... aim... fire! Take the safety off first, George. Gees... you call yourself a scientist? Ready... aim... fire!"
"Oh, no, not my brand new spectrometer!..."
"Look... Blue light! Woooohoooo!"
Anyway, because the redshift comes from the space itself expanding, it's proportional (I think it's a linear effect, I don't remember too well) to the distance between you and the object under observation. Yes, there is some Doppler style redshift, but that is not what's generally meant when an astronomer says "redshift". Also, cosmologists use redshift (z) as their primary variable in many equations. Most cosmologists measure distance in redshift, instead of cgs or mks length units.
Down with Saudi Arabia!!!
The questions about how does a continuous beam of light have its frequency changed might be better rethought using a particle model of light.
The researchers themselves refer to photons being absorbed and re-emitted with a different frequency at the shockwave fronts, so the photon model seems more suitable for current understanding of the phenomenon.
Truly. It is a shit magazine with very little content. Little wonder it is a favorite of intellectually-challenged slashdot eidtors.
I may have misunderstood the article, but I didn't get the impression that a single crystal could produce different frequencies. One crystal, made of a certain combination of layers, would be able to change light from red to green, another crystal could change light from white to blue, etc. So you would still need separate crystals for each color. You couldn't simply change the composition of the crystal on the fly to give it different light-changing properties.
It may be that you can change these crystals on the fly by sending different types of current through them. I don't know enough (read: anything) about the materials that are used to make them.
By taking sunlight and turning it into microwave radiation, you could get far greater efficiency out of the generation of electricity.
This would make microwave beaming satellites highly efficient. The current idea was to have huge solar arrays which would of course alter the look of the sky during the day or night. These would convert some of the light into energy and probably reflect the rest of lose it as heat. The elctricity generated would produce a microwave signal which would be beamed down to a ground station and converted back into electricity. With this new technology, they could have far smaller arrays which convert the light directly into microwaves and transmit, eliminating the overhead of going from light->electricity->microwaves->electrici ty on the ground.
Instead you would have light->microwaves->electricity on the ground.
And you wouldn't need a mile long array of cells to collect enough power to make it worthwhile because your effeciency would be extremely high.
--Won't that be grand? Computers and the programs will start thinking and the people will stop. - Dr. Walter Gibbs
Truly. It is a shit magazine with very little content. Little wonder it is a favorite of intellectually-challenged slashdot eidtors. Yeah, those eidtors are jerks. Good thing the editors keep 'em in line.
http://xkcd.com/386/
Holy Cow! Imagine that! People have only been doing Brullion Scattering for 30 years to shift frequencies of light! Sorry, this is a science non-story, and is merely more incremental progress.
Entropy increases. This is a fundamental and inescapable law, and I'm suprised the article didn't address this point. Of course, I suppose when scientific discoveries get to the media before they get a chance to go through reasonable peer review, I guess you can't expect a whole lot of scientific accuracy.
File under 'M' for 'Manic ranting'
The radiation selectivity property was discovered by observing the phenomenon of Cherenkov radiation inside the photonic crystal.
u o_science_2003.pdf]
For further more detailed technical information, a PDF of the paper is here [http://physics.ucsd.edu/~drs/publications/2003/l
Photonic crystals fall under a broader family of materials called "metamaterials".
Future research note: Software-programmable metamaterials will create wonderfully exotic applications.
Cheers
Andrew
I can just here Scotty know..."We need to replace ar supply of photonik crystals Captain."
There once was a man named "Bright" :)
Who could travel much faster than light.
He set out one day
In a relative way
And came back the previous night!
if all light would travel thru you, your eyes, working on the principle of REFLECTION of light, would become useless... Beware the invisible man, stumbling his clumsy way around! oh, well...
Bah, gimme a call when Light Sabers become available :)
Does this mean we'll finally be able to get X-Ray specs?
If I seem short sighted, it is because I stand on the shoulders of midgets
The first thing that pops in my mind is running a finger down a vibrating string, like on a guitar. The note gets higher and higher as the string is forced to vibrate in less and less linear space. This sounds like the optical equivalent.
Learning HOW to think is more important than learning WHAT to think.
This could be used to create the first real optical multiplexer ?
Incoming traffic could be converted to a specific frequency depending on the destination. Special filters could then be used on each outgoing channel, to filter out the undesired frequencies.
A second "frequency conversion" could then retransform everything back to the correct spectrum band.
E = h * nu
If you change nu (the frequency of the EM wave), the energy of the wave must also change. Where does the energy go or come from? e.g. if shifting optical light waves to to X rays, there must be an energy input. Does this come from the mechanical vibration of the crystal?
"Huh, that's not supposed to happen..."
WARNING: there is a trojan on your
We'll finally be able to get a pair of those glasses that they sell in the back of hobby magazines... that actually work!
Of course, you'd need lots of incident X-rays for that. Damn this atmosphere and magnetic field!!!
nuke the moon
IANAP[hysicist], and so I have some questions about this process.
What I know:
So, when light is converted to a higher frequency (shorter wavelength) where does the necessary energy come from? The shockwave? What about when it is converted to a lower frequency (longer wavelength)? Where does the excess energy go? If the conversion really is 100% efficient (I'm a bit skeptical of that claim), then just imagine the solar panels we could have; sucking up all the UV raining down on us and emitting a soft red glow.
Fascinating stuff. I've got to study more optics and electromagnetic physics.
Initially they will generate shock waves by shooting bullets at photonic crystals.
Who says science isn't fun?
-R
interstellar medium, like in dust clouds...interesting
Does this remind anyone else of the Ledbetter effect that Heinlein described in his "Sixth Column" novella?
Seems like there was another Heinlein story that used a light wavelength shifter as an energy resource - one that ultimately powered moving sidewalks...anyone remember the title of that story?
...when he shot out his TV. He was truly ahead of his time.
But they do occur with alarming frequency.
"He who laughs last, didn't get the joke."-Cap
Of course I haven't seen their simulations, but where does this "near 100%" figure come from? The first test is going to use a bullet (!) and they are projecting that a more refined version will use sound waves. Something has to produce those sound waves, and the waves have to be powerful enough to alter the characteristics of the crystal.
Now I understand that in theory a light wave at a given frequency could transform to a higher frequency and lower intensity (conservation of energy is not violated), but that's analogous to changing the gear ratio on a motor. A gear system always introduces some loss.
Now, given that any practical implementation of this will require a wave generator that's likely to make some noise, I don't see it ending up in lightbulbs or solar cells. If you want to get more light to a solar cell, focusing a mirror on it and keeping it cool is probably more practical.
However, the medical imaging tech sounds like a great application. Noise from medical scanners is an acceptable part of that experience.
For all intensive purposes, "whom" is no longer a word. That begs the question, "who cares"?
Since the shift requires shooting the photonic crystal with a bulled, you'd have a room full of drunk horny single people shooting guns. Darwin award, anyone?.
I wonder what this would do to say a modulated light beam carrying information. Since I'm a DSP guy the first thing that came into my head was "aliasing". Yeah, I know we're not sampling here, but that's what I thought of.
:) A DSP one.
So let's assume we have a modulated light beam carrying some information. I don't think the information would be affected if it does not require the whole bandwidth of the new light frequency.
But what if it does? What frequencies will get chopped out? Or does the whole stream become unreadable? Anyone got any ideas? I know this sounds crazy, but what if, just what if nothing is lost? I can immediately see applications of "slowing down information transfers". And suppose certain frequencies are chopped...could that be used to implement a kind of bandpass filter?
Quite fascinating actually. By the way, I need a job
Find a job you like and you will never work a day in your life.
Mod Parent Up!!
I always tought that energy is downgrading and entropy is increasing, ie at the big bang the energy was all highly condensed high energy and it downgrades to background radiation. Could you change this background radiation back again to a higher frequency/energy wave?
So now in a few years might we be able to light our homes with the excess heat from overclocking our PCs? Perhpas drive some cool fiberoptic case mods?
Oh I can't wait for this one to be commercialized, but chances are I'll be too old to be l33t by then. =(
My $0.02 will always be worth more than your â0.02, so
Here's your comments in a nutshell:
Holy worthless. Score 4 on this guy? WHY?
-malakai
-Malakai
A Dragon Lives in my Garage
I didn't know that, guess I need to RTFM on /. :-)
from turning heat into light, or even into prized terahertz rays
I don't see why this would be prized. Light is in the terahertz already. 380THz to about 790THz is visible light.
Current methods of shifting the frequency of light involve four-wave mixing (nonlinear photon-photon interaction), stimulated Brillouin scattering (photon-acoustical phonon interaction) or stimulated Raman scattering (photon-vibrational phonon interaction). The article mentions that current methods require intense light for the nonlinear interactions to occur, which is true, but the new method suggested is just a complicated form of Brillouin scattering to trap light in a photonic crystal for the interaction to be more efficient, and it too requires an intense acoustic shock wave, which can even destroy the crystal. I don't see how this would be superior to existing methods in an experimentally realizable situation. Furthermore their result is only computer simulation, and any self-respected optical scientist knows that simulation accounts for nearly nothing, if you have no experimental demonstration to show. I'm made even more skeptic after one of those guys (Marin Soljacic) came to my school to give a seminar talk and he emphatically stated that Doppler shift was NOT the reason why the light frequency was shifted and made a really lousy explanation. I'm not holding my breath.
Slashdot editors can't spell. But I suppose subtlety is lost on this crowd.
Seems it has been accepted. Here is the abstract I found in the "Accepted Papers" section of PRL's site.
The article on newscientist also mentioned another interesting phenomenon: light changing frequency when a very powerful (megawatt to gigawatt range) is sent next to it. How does this work? I thought EM waves are doesn't interacts with each other; or the presence of some matter is required for this to happen?
actually, unlike most of science i can't figure out how this will help. Did i miss something or is the project doomed since all science ultimetely goes back to porn.
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then i guess we wouldn't cover our eyes with it genius.
Imagin[e] a future where biology and technology merge. We're now creating computer programs using the principles of natural selection and random mutation --- the basics of Darwinian evolution. We may grow telephones, but manufacture cabbage. -- Danny Hillis, MIT Media Lab
That kind of thinking got him fired from Disney R&D
Best Buy can have you arrested
Remember, man's technological masterpiece, our crowning achievement, the Internet, is a pornography distribution system.
http://www.accountkiller.com/removal-requested
render an object invisble to an observer?
Mongrel News all the news that fits and froths
...you could make with this technology were it in production. Those old Durons and heat-sinkless video cards could translate to some funky server room back-lighting. Just think of the kinds of case mods which would be possible...
-guanno
All I can think of here is lasers.
If you can shift the wavelength of a cheapie red laser to become a non-cheapie blue laser, you could utterly revolutionize every aspect of disc-based (CD/DVD/etc) storage and retrieval.
Wouldn't it be impressive if all lasers worked on the exact same technology, with the exception of each having a different vibrating color-shift crystal in them? Make them interchangeable and then anybody can have any laser of any color.
Blue light is more-powerful than red light, because the wavelength is shorter; each blue photon contains slightly more energy than a red one. So, I suppose my biggest question is: If I have a 5mW red-emitting laser, and I pass it through one of these crystals to shift its emitted wavelength to blue, how close to 5mW will the crystal's output power be?
Reinvent the wheel only at either a lower cost, greater effectiveness, or your own personal enrichment and satisfaction.
Actually absorbsion would work, unless you eclipsed something and in space there would always be something behind you, a star or distant galaxy, but at long enough range, you would be effectively invisible unless they did a sweep with a telescope to enhance that area to notice the missing background stars and such.
:)
So they wouldn't see the hole unless they were looking for it most likely or you were close enough to noticibly block out background objects. Otherwise their scanners (assuming radar here) would be absorbed but that would be no different to them than there being nothing there and the radar beam never reflecting back and continuing on into space. They would never know if it had hit something or kept on going forever. That is how stealth technology works today with radar absorbing and scattering materials.
However, there IS a way to know if the radar hit something. That is with entangled photons. You create entangled radar basically. You create a pair of entangled photons at radar frequency and send one out, the others you somehow hold in a loop on board the ship and a computer will see if they deflect as if they encountered something. I suppose you could kick the frequency of the ones you keep up and put them in a fiber optic loop... Hmm of course observing them probably destroys them, so not entirely sure if that would work. But its a fun thought experiment.
They have used a similar technique to see inside objects without getting an actual reflection from that object by observing the reaction of one set of the entagled pair of photons kept in a separate laser beam from the ones "injected" into the object. They were able to create a laser image of the inside of the object that way. Quite cool.
Hmm another thought occurs. If you have a pair of entangled photons and you frequency shift one of them, what happens to its sibling? Will it also change frequency or will it become disentangled from the other one?
If the sibling would change frequency, that would be awesome. Imagine... You have a patient with a deep brain tumor, the kind you can't take out without seriously messing them up or killing them. So you entagle photons in the form of radio waves which can pass through their head and beam them at the person, using a frequency which enables a fairly tight beam. A computer calculates then the photons will reach the tumor after coming out of the emitter and changes the sibling into x-rays or gamma rays causing the siblings inside the patient to also change and fry the tumor. All without any cutting or surgery at all. Of course the amount of time it takes the photons to go from the emitter to the tumor is exceedingly small. So if the time to change the photons is too long, you will miss the tumor and maybe the patient all together, frying something way behind them.
Also, and correct me if I'm wrong, the change in frequency is gradual as the photons bounce around in the crystal, so the photons may be absorbed when they hit a frequency far below x-rays which may be absorbed harmlessly by the tissue... However that may not be until infrared so you might be able to kill the tumor by heating it that way instead of using ionising radiation.
Just thoughts... free free to nitpick and add to them
--Won't that be grand? Computers and the programs will start thinking and the people will stop. - Dr. Walter Gibbs
Well, maybe we could finally see all the great stuff that happens in the Octarine-color spectrum!
It would make for some really great Darwin Award stories...
This is all the budding Jedi Religion needs; an iconic weapon for every member to go out and get. And where there's Christianity, there's Satanism; what happens when some idiot Jedi decides that he'd rather be a Sith lord?
In breaking news, a lightsaber wielding Jedi, calling himself Darth Mangle, killed several bank customers and then himself. A note found on his person declared "i told u i was hardcore."
We need to develop blaster pistols first. Then we can pull a Raiders of the Lost Ark on these idiots.