Large-aperture transparent beam steering screen based on LCMPA

A large aperture transmissive step-steering screen composed of a liquid crystal microprism array (LCMPA) deflector and a 90° twisted nematic liquid crystal (TN LC) polarization modulator is developed. The designed 3 in. (7.62 cm) device provides a steering angle of 0.95° that differs from the projected value by only 1.26% and the angular difference caused by dispersion is less than 5%. Using two-layer cascaded screens a three-direction beam steering system for stereoscopic displays is achieved with a steering step of 0.95°, undesired residual polarization contrast less than 2%, and high optical uniformity.