Is it possible to split a single light beam into two beams of opposite circular polarization? A properly oriented calcite crystal will separate an unpolarized beam into two beams, one vertically polarized and one horizontally polarized.  Other polarizers pass just one polarization and absorb the perpendicular one.
Is there a device that splits an unpolarized light beam into a right circulaly polarized one and a left circularly polarized one, instead of just absorbing one or the other?
(If so, please tell me where I can buy one.)
If not, is this theoretically impossible?
 A: Yes, this should be possible using a chiral material or the Faraday effect.
First example.
Second example.
However, the calcite + wave plate system is probably a lot easier.
A: I believe 3D movies use opposite circular polarizations. This video explains how exactly they work - midway through he mentions that a mirror surface will change the orientation of the circular polarization. 
http://www.youtube.com/watch?v=quoySiCVFfw
good luck
A: Linearly polarized wave can be represented as a superposition of a right circular wave and a left circular wave.
We can use device like Fresnel's composite prism in which we use subtances such that refractive index for right circular wave is different than the refractive index for left circular wave.
now,if we send plane polarized light though the prism since speed of a wave depends on the refractive index sometime left circular wave part (of the the linearly polarized wave)moves faster through the prism and sometime right circular wave part and thus left and right circular wave refracted in different angles and eventually get seperated.
