Novel polarized light emitting illumination systems for LCDs

A new, simple polymer-bilayer illumination system is presented which efficiently emits linearly polarized light for use, for example, in liquid crystal displays. Polarization of incoming light is accomplished through polarization-selective reflection at the interface between an optically isotropic light guide and a birefringent top-layer mounted thereon. Light of one polarization direction is coupled-out from the latter layer by means of an appropriate relief structure. Light of the other polarization direction is trapped in the isotropic waveguide and may be recycled, which ultimately permits polarization efficiencies that approach unity.