Towards a linearly polarized light a half-wave plate is placed. The plane of oscillation of the incident light makes an angle with the optical axis of the plate. How to determine the polarization of light passing through the plate?
Linear polarization is maintained, but the plane of vibration will be inclined to the optical axis at an angle β=(-α), i.e. will turn to the corner 2α. In particular, when α = 45º, the plane of oscillation will rotate by 90º.