Polarizing Cube Beamsplitters split randomly polarized beams into two orthogonal, linearly, polarized components-S-polarized light is reflected at a 90deg.Angle while P-polarized light is transmitted.
Beam splitters are optical components used to split input light into two separate parts. Beamsplitters are common components in laser or illumination systems.
Due to the rotation activity of natural quartz crystal, it also can be used as polarization rotators so that the plane of input linearly polarized beam will be rotated at special angle which is determined by the thickness of quartz crystal.
Plane polarized beam is not welcomed in some circumstances such as reflecting spectrometer. A depolarizer will change the plane polarization into a mix of polarization states by scrambling up the polarization,