Anaglyph of a circularly polarized light wave #2.
3D stereoscopic anaglyph (view with red-green or red-cyan glasses) of a circularly polarized light wave. Linearly polarized light is converted to circularly polarized light by slowing one component of the field. Effectively, the light is given a twist. This is achieved by using a material that transmits light at different speeds depending on its polarity. This happens because of the way the atoms are arranged in the crystal. In the diagram above, you can see a linearly polarized light wave (simple wave entering at left) oriented at 45 degrees to the system. Projected onto the vertical and horizontal planes are the vertical and horizontal components of that wave (equal and in phase). When that wave passes through the material, the vertical component is slowed down so that it is out of phase with the horizontal component. When it is a quarter wavelength slower, the resulting wave is helical. To an observer receiving the circularly polarized light, the electric field of that light will appear to rotate rather than just bob up and down. Hence the term circular polarization.