6.1-7 Half-Wave Retarder. Consider linearly polarized light passed through a half-wave retarder. If the polarization plane makes an angle 0 with the fast axis of the retarder, show that the transmitted light is linearly polarized at an angle -6, i.e., it is rotated by an angle 20. Why is the half-wave retarder not equivalent to a polarization rotator?

6.1-7 Half-Wave Retarder. Consider linearly polarized light passed through a half-wave retarder. If the polarization plane makes an angle 0 with the fast axis of the retarder, show that the transmitted light is linearly polarized at an angle -6, i.e., it is rotated by an angle 20. Why is the half-wave retarder not equivalent to a polarization rotator?