Design and fabrication of an integrated polarized light guide for liquid-crystal-display illumination

An integrated polarized light guide was designed and fabricated for use as a liquid-crystal backlight with emphasis on uniformity of the light and conversion of p-polarized to s-polarized light. Two different micro-optical structures were fabricated both on the top and the bottom surfaces of the light guide. On the top surface, a subwavelength grating separates s-polarized and p-polarized light to achieve a polarization-conversion efficiency of 69%. A 1.7 gain factor of polarization efficiency was obtained to increase the utility of light for liquid-crystal illumination.