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Crystals that modify the frequency of light.

  1. May 27, 2003 #1


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    This is an interesting new development.
  2. jcsd
  3. May 27, 2003 #2


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    Fascinating !

    This could mean a whole new generation of
    photovoltaics, lasers and more ! :smile:

    Live long and prosper.
  4. May 27, 2003 #3
    I was asking about something like this a few weeks ago. Glad to hear they can do it. Can someone say "X-Ray specs"? :p
  5. May 29, 2003 #4

    Claude Bile

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    The theory and computer modelling is nice, however there is a lot more research to be done before we can begin to observe these effects in practice. Fabricating such devices is the 1st big challenge.

    Frequency shifting is not the only thing that Photonic Crystals are capable of, many experts beleieve that Photonic Crystals will form the basis for Optical Integrated Circuits when their potential is fully realised.
  6. May 29, 2003 #5

    wow... if i am understanding this correctly, could it bounce back a frequency of light that the human eye cannot percieve thereby "cloaking" it?
  7. May 30, 2003 #6
    Very interesting would be to shift radiation invisible to eye so that we can actually peek how it looks like.
  8. May 30, 2003 #7
    dont we already do this everyday? it known as a "false color image"
  9. May 30, 2003 #8
    Isn't that what the predator used to be invisable?
  10. May 30, 2003 #9


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    Re: cool...

    No. It would simply register as the abscence of light - ie. black. For real invisibility as we think of it, we need to mask with lights fitting in with the background.
  11. May 30, 2003 #10

    Invisibility could work if you used the material on both sides to increase the frequency of the light to make passing though your body easy for the light rays but your bones are harder to see thought
    Ex. X-rays. Even so, at a distance it would seem to make you invisible. There will most likely be some distortion of sight due to the change in the index of light between the crystal and the environment and your body. I know little about these crystals so I am just assuming they would work like glass and you can have it in a layer to coat the object.
  12. May 30, 2003 #11


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    Hmm.... interesting... that might just work... You mean use the x ray as a way of transmitting the image from one side of your body to another?

    Apply for military funding immediately! :smile:
  13. Jun 1, 2003 #12

    Claude Bile

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    The manipulation of light in this manner can only possibly work on micron scales, since the method relies on Bragg reflections from adjacent lattice planes in the crystal. The mechanism of the doppler shift (phonon interactions) could not possibly preserve any image that is input into the crystal in the first place. You put light in, you get light out of a different wavelength (colour), simple. Not as impressive as X-ray vision, but to laser and optical physicists it is a totally unprecedented degree of control.

    Also, the original article claims that this process in 100% efficient, which is not entirely accurate. It is possibly 100% efficient insofar as you get as much light out as you put in, however energy is still required to generate the acoustic shock waves that provide the effect in the first place.
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