Chien-Chuan CHEN and Cheng-Huan CHEN

Power Mechanical Engineering Department, National Tsing Hua University, 101, Section 2, Kuang-Fu Road, Hsinchu 30013, Taiwan, R.O.C.

(Received December 9, 2008; Accepted April 30, 2009)

The surface of a solid plate light guide patterned with nanostructure composed of bilayered dielectric and metallic stripes is capable of partially transmitting only one of two orthogonal polarizations while reflecting most of the other, and therefore performs as a reflective polarizer. The polarization dependent transmittance, polarization efficiency and extinction ratio of both parallel and cross stacking of the bilayered nanostructure have been analyzed for all radial and azimuthal light incident angles. Both configurations have shown overall polarization efficiency above 98% over the visible spectrum, and exhibit an extinction ratio above 1,000 within a specific range of light incident angle. Accompanied by a proper polarization converter and light extraction pattern, the polarized light guide can provide a high efficiency or even a polarizer free illumination optics for an application where a planar illuminator with polarized light is required.

Key words: polarization, beam splitters, liquid-crystal devices, wire grid polarizer, extinction ratio