# Plane polarized light?

I have heard about plane polarized light: light wave which has vibration in one plane. My curiosity forces me to ask a doubt, is there any way to produce polarized light wave which has vibrations in two planes? If it exists, then what are the uses of such a light wave?

UPDATE: I make my side more clear, I would like to know that is there a way to produce a light wave which has two planes of vibrations?

• For Circular polarised light the field vectors rotate uniformly about the direction of propagation. Look up circular polarised light. – WetSavannaAnimal Dec 5 '14 at 12:59

If we try to polarize the same beam of light in two planes, or if we mix two planar polarized beams, the light will interfere.

If the phases of two beams will be identical, then we get 45 degrees polarized light.

If the phases of two beams will be different, then we will get so called circular polarized light

In other words, any sort of polarized light can be regarded as a sum of two perpendicular polarization. This is called superposition principle.

yes, you can. Actually an application is googles for 2d movies. You project on the screen two different images (that is why you see it blurred when watching without the googles), each one has a different polarization. Each plastic filter in the google is a polarizer, and each eye is tuned to a different polarization. So that each eye see only one of the two projected images, as teh images are slightly differect, this produces a steroscopic depth effect. Note: modern 3d googles actually use opposite circularly polarized lights instead of perpendicular polarizations, but is only for technical reasons.

• I'd hardly count being able to observe stereoscopic (the term "3D" is inaccurate) regardless of head orientation as "technical reasons" :-) . The use of circular polarization was a significant step in making stereoscopic video a reality. – Carl Witthoft Dec 5 '14 at 13:04
• I agree, just didnt want to go into perhaps confussing) details, as the original OP asked for linear polarization. But I should have. Thanks for the comment! it improved the answer – Wolphram jonny Dec 5 '14 at 13:07
• @ Wolphramjonny I think this is not the answer to my question. Because, I have asked for a light wave which has only two planes(ordinary light vibrates in all directions) or vibration in two planes.But in your answer, each eyes will get different polarized light( but the polarization for an eye is always the same because the polarization of the google does not change), I do appreciate your answer because I didn't know the principle behind 3D movies, but I think that the answer is irrelevant to the question( I don't know whether I am correct or not. – RogUE Dec 5 '14 at 13:45
• @Wolphramjonny If I went wrong, please correct me). – RogUE Dec 5 '14 at 13:46
• one simple way is to use two single polarized generator in series (the light will mix). Another is a single source of random light (like that from a bulb), split the beam in half with two mirrors, pass each trough a different polarizer (same as the one used in googles), and reunite again the spleated beam into one (using mirrors). – Wolphram jonny Dec 5 '14 at 14:00