Polarization of Light After Reflection from Surfaces

[Ryker]

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.

 

[0xDEADBEEF]

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.

 

[Andy Resnick]

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.

 

[Ryker]

Thanks for the replies.

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.

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.