# 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?

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Actually, it seems like the calcite crystal followed by two different delay plates might do the trick. But this seems like a cheat to me. I guess I'm looking for a one step solution. – Jim Graber Jul 23 '12 at 0:09

## 3 Answers

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.

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Thanks for an excellent reference. – Jim Graber Jul 23 '12 at 10:36

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

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Welcome to Physics.SE! Our policy here is to disallow answers which are little more than a link. Could you edit this answer so that it contains at least a few paragraphs of conceptual explanation of the phenomenon? You can obviously link to the video for full explanation :) – Manishearth Jan 22 '13 at 5:54

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.

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