Mass production method for polarisers

A method of mass producing polarisers comprises designing by rigorous diffraction theory an optimised grating profile, replicating the profile in a polymer or other substrate, and slope evaporating a metal onto the substrate. The angle of slope evaporation, the metal, and the thickness of the metal are optimised for a given wavelength using vigorous diffraction theory. The polariser may be coated with a protective coating, such as an acrylic based lacquer or Magnesium Fluoride (MgF2). The optical effect of the coating is also taken into account in the design using rigorous diffraction theory.