Liquid Crystal Devices Based on Photoalignment and Photopatterning Materials

Liquid crystal (LC) display and photonics devices based on photo-alignment and photo-patterning LC cells are developed. A fast switchable grating based on ferroelectric liquid crystals and orthogonal planar alignment by means of photo alignments. Both 1D and 2D gratings have been constructed. The proposed diffracting element provides fast response time of around 20 mu s, contrast of 7000: 1 and high diffraction efficiency, at the electric field of 6V/mu m. A switchable LC Fresnel zone lens was also developed with the efficiency of similar to 42% that can be further improved, and the switching time for the 3 mu m thick cell is similar to 6.7 ms which is relatively fast in comparison of existing devices. Thus, because of the photoalignment technology the fabrication of Fresnel lens became considerably simpler than others. A thin high spatial resolution, photo-patterned micropolarizer array for complementary metal-oxide-semiconductor (CMOS) image sensors was implemented for the complete optical visualization of so called