Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Shifting from IR to visible spectrum - Help pls!

  1. Feb 24, 2009 #1

    I'm trying to think up a way to shift IR rays into visible light spectrum so that the human eye can effectively see the IR image. Is it possible to do such a feat with something as simple as goggles made from a special material (e.g. anti-stokes pigments)??

    If not possible with such simple devices, what is actually the most portable way of doing such a shift to visible light?? (something like night-vision goggles are too expensive and complicated... something more spartan) =D

  2. jcsd
  3. Feb 24, 2009 #2


    User Avatar
    Science Advisor
    Homework Helper

    It's generally not possible. Firstly the coating wouldn't preserve the direction of the photon it would re-emit into 4pi so you could detect a glow but not see the image.
    Then the efficency of these conversions are very-very low, you aren't going to get a naked eye signal out unless you are viewing a very bright IR source.

    There are dyes which you can excite with a UV/Visible preflash and then they sit in a metastable state until an IR photon comes along and they decay.
    They used to be coated on CCDs to make (poor) ID detectors.

    What kind of infrared (what temperature source and how bright) do you want to see?
  4. Feb 24, 2009 #3


    User Avatar
    Staff Emeritus
    Science Advisor
    Homework Helper

  5. Feb 24, 2009 #4


    User Avatar
    Gold Member

    People do this all the time. You want to create a visible image of the IR information? There are a lot of ways to pull this off. They are not always really accurate visual translations, but if all you want to do is target and kill somebody, the systems are already highly developed.
  6. Feb 24, 2009 #5
    in my impression, someone use parameter-up conversion to do this
  7. Feb 24, 2009 #6


    User Avatar
    Science Advisor
    Homework Helper

    laser viewing cards use dyes pumped by the uv in sunlight, http://www.cascadelaser.com/ircards.html but they aren't what you would call sensitive.

    Some lasers use KDP (Potassium Dideuterium Phosphate) crystals to double IR (usually 1064nm YAG) to green (532nm)
  8. Feb 27, 2009 #7
    While you can use non-linear optics to double or even sum wavelengths you need a highly coherent beam of high energy(ie laser) with a strongly birefringent crystal so that you can get phase matching. Not something that can be done without the correct set up and not something that will work to convert stray IR to a visible wavelength.

    Just didn't want anyone to get the wrong idea:)
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook