Optical polarization conversion

[lichen]

From a classical perspective, linearly polarized light can be converted to circular by introducing a phase shift between the orthogonal modes.

Could someone give me an explanation of how this works from a quantum mechanics perspective, starting from the fact that each photon has angular momentum either left spin or right spin?

I suppose this means that linearly polarized light has an equal number of the left/right spinning photons, but what happens when this light is converted to right-circularly polarized? Are the left spinning photons converted into right spinning ones??

 

[azntoon]

From a quantum mechanics perspective, linearly polarized light is composed of photons that all have the same angular momentum. When the light is converted to circularly polarized, the phase shift between the orthogonal modes causes the left-spinning and right-spinning photons to be out of phase with each other. This means that they no longer have opposite angular momentum, and instead they both have the same angular momentum. As a result, the light will appear to be circularly polarized.