US Patent 7800823 Polarization device to polarize and further control light

A polarization device includes an optical stack with a diffraction grating and a wire grid polarizer with one disposed over the other. The wire grid polarizer includes an array of elongated, parallel conductive wires in accordance with PWGP<λ/2 where PWGP is the period of the wires and λ is the wavelength of the light. The diffraction grating includes an array of elongated parallel dielectric ribs in accordance with PDG>λ/2 where PDG is the period of the ribs.