Polarizing grating color filters with large acceptance angle and high transmittance

We design and simulate a polarizing color filter with a sub-wavelength metal-dielectric grating. It manifests several advantages: a large acceptance angle (up to +/- 50 degrees), high transmittance (74.3%-92.7%), low absorption loss (similar to 3.3%), and a high extinction ratio. This polarizing color filter can be integrated into a liquid-crystal display (LCD) backlight system to simultaneously recycle the light according to its color and polarization. In combination with a specially designed directional backlight, this newly proposed LCD system can theoretically improve optical efficiency up to similar to 2.5x, and also provides a large ambient contrast ratio and a wide view. Our approach enables an ultra-low-power LCD without using the complicated field-sequential-color technique. (C) 2015 Optical Society of America