1. Limited time only! Sign up for a free 30min personal tutor trial with Chegg Tutors
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Does linearly polarized light become randomly polarized after diffuse reflection?

  1. Nov 4, 2012 #1
    I was wondering what happens with linearly polarized light when it is reflected from a surface such as paper? Since it undergoes diffuse reflection, it is scattered in all directions, but does it become randomly polarized, as well? I can't really find an answer to that anywhere, so I'd be grateful for any responses.
  2. jcsd
  3. Nov 5, 2012 #2
    No, it keeps most of its polarization otherwise 3d cinema wouldn't work. But it is different when the photons get absorbed by a die for example, or when there is dichroism, optical rotation or multiple reflection.
  4. Nov 5, 2012 #3

    Andy Resnick

    User Avatar
    Science Advisor
    Education Advisor

    It's true some 3-D cinema uses polarization effects- but those also require use of a metallic 'scrim', which is why the polarization states are maintained. Scattering off a rough dielectric will randomize the polarization.

    Rough surface scattering is the subject of countless books and ongoing research- Ogilvy's book is a good place to start, if you can find a copy.
  5. Nov 5, 2012 #4
    Thanks for the replies.
    Yeah, this is what I heard today, as well. That diffuse reflection does randomize the polarization, but that if you have some metal coating, the polarization can be preserved. I was told that's why, like you said, 3D cinema can't just use any projection screen, but one with a metallic layer on top of it. So I guess paper randomizes polarization, while a mirror would preserve it, even if reflection was diffuse.
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook