High-efficient liquid crystal polarization gratings for autostereoscopic 3D display

There are many implementations of naked-eye 3D display technology. Diffraction-based multiview 3D display is one of the most promising research directions. Several viewpoints are built where human can get different image in their eyes to get stereoscopic perception. The core element in this solution is grating, which diffracts the light to a specific direction, usually the +1 or-1 level. Compared to binary grating, a novel geometric phase element, liquid crystal polarization grating (LCPG) has many advantages in acting as the core element. First, LCPG shows periodically cycloidal texture and can diffract with nearly 100% efficiency which minimize the high order and concentrate the energy on ±1 order. Second, its polarization-sensitive character can be used for making a polarization-dependent display. What's more, the grating is spin coated on the substrate and appears a super thin film for less than 10μm. Photo alignment technology is used for fabricating LCPGs. We proposed an interference-free and single exposure method using birefringent prism and wave plate. The fabricated LCPGs appear >99% efficiency and has potential to expand the effective waveband. This method is effective, robust and low-cost, which has potential for commercial applications.