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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."
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
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
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
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?
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.
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 !
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
"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
Uhm, it wouldn't mess up anything. A 1280*1024 colourdisplay is essentially a 3840*1024 "monochrome"-display (each R,G,B being separate elements). If you wouldn't need separate elements, you'd have a true 3840*1024 colour display, which would be vastly superiour to sub pixel rendering .. :)
it's in my head
Ummm... How would you get white (red, green, and blue at the same time)? I suppose that you COULD rapidly switch between multiple frequencies to get a simulated white, but the article did not explain how much control you could get over the process... Perhaps a single crystal would only provide a fixed shift (red->blue), and if you wanted red->green, you use a different crystal.
Also, each pixel would need its own crystal and "hammer" (probably a piezo element). This would probably be even more expensive than current flat-screen televisions.
Just one more note -- if you have little crystals being hit at 60Hz (assuming a progressive scan display), that sucker would humm like crazy!
"-1 Troll" is the apparently the same as "-1 I disagree with you."
how cool - finally we can have computers full of flashing lights Just like in the movies...
Slashdot - The one stop shop for procrastination
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.
Sure, if you shift the frequency down far enough. Problem is, you would only be able to see the world in x-rays. And lemme tell you, it's pretty dark at that end of the spectrum. The atmosphere filters out most of the higher-range radiation (a few dozen kilometers of air is about as effective as 8 centimeters of solid lead), which is why x-ray machines are all about the generation of radiation; seeing it on film the easy part.
If you want comic-book style x-ray specs, then we're talking about short microwave and far-infrared radiation. Then you just shift the radiation back up into the visible spectrum and you can see through clothes, flesh, fairly un-dense stuff like that.
Dyolf Knip