Medway Optics fabricates high efficiency AR coated prism polarisers from Calcite (CaCO3), Barium Borate (a-BBO) and Yttrium Vanadate (YVO4) giving polarisation coverage from 280-4500nm. The following prisms are available as standard: Glan Thompson, Glan Taylor, Marple-Hess, Walloston and Rochon polarisers and beam splitters.

A beam of light incident on a parallel plate of a birefringent crystalline material (anisotropic) will be split into two separate orthogonally polarised beams, provided the direction of the incident beam does not coincide with the optic axis of the crystal. The emerging beams propagating at different speeds with different index of refraction will have different polarisation where they do not overlap.