Polarization by half-silvered mirror?

[nickyrtr]

When light is partially reflected by a half-silvered mirror, as in an interferometer, do the reflected and transmitted beams have different polarizations? Is this answer the same for all half-silvered mirrors, or does it depend on the metal coating used and/or the optical properties of the transparent substrate?

 

[Andy Resnick]

It depends on the details, but probably not- the beams will not be polarized differently. If the light is incident onto glass at the Brewster angle, OTOH, there will be a difference in polarization states of the two beams.

 

[Meir Achuz]

The reflected light will have a different degree of polarization than the incident light unless the incident light is 100% plane polarized either in or perpendicular to the scattering plane. The transmitted light will have the same polarization as the incident light.