How does reflection affetc the polarization of light?
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If you have an incident ray that is polarized with the E field up and down (in the plane containing the incident ray and the normal to the surface), then when that ray is refracted, it contains a component of electric field that is perpendicular to the refracted ray (and still in the same plane).
The reflection is actually caused by the motion of electrons in the medium. Now you can see that the electrons, which move along the direction of the E vector, are moving parallel to the direction of the reflected beam. An electrical dipole that is oscillating can send a wave in all directions - except the direction it is pointing (if you think about it, looking at the dipole "end-on" you don't see it moving: if it doesn't seem to be moving, it shouldn't be seen to be radiating towards you...)
So there it is - for this very special orientation, the reflected light must be fully polarized. If you do the math carefully (see Fresnel's equations), you will see that you will have somepolarization at any angle - again, because the amount of polarization in the reflected light depends on the ability of the dipoles in the material to excite a reflected wave).
The reflection is actually caused by the motion of electrons in the medium. Now you can see that the electrons, which move along the direction of the E vector, are moving parallel to the direction of the reflected beam. An electrical dipole that is oscillating can send a wave in all directions - except the direction it is pointing (if you think about it, looking at the dipole "end-on" you don't see it moving: if it doesn't seem to be moving, it shouldn't be seen to be radiating towards you...)
So there it is - for this very special orientation, the reflected light must be fully polarized. If you do the math carefully (see Fresnel's equations), you will see that you will have somepolarization at any angle - again, because the amount of polarization in the reflected light depends on the ability of the dipoles in the material to excite a reflected wave).
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